Techniques for reporting channel state information (csi) for an unlicensed radio frequency spectrum band

ABSTRACT

Techniques are described for wireless communication. One technique includes receiving a service via a component carrier, wherein the component carrier may be in an unlicensed radio frequency spectrum band. One or more signals transmitted on the component carrier may be measured to estimate channel state information of the component carrier in the unlicensed radio frequency spectrum band.

CROSS REFERENCES

The present application for patent is a continuation of U.S. patentapplication Ser. No. 14/567,573 by Luo et al., entitled “Techniques forReporting Channel State Information (CSI) For an Unlicensed RadioFrequency Spectrum Band,” filed Dec. 11, 2014, which claims priority toU.S. Provisional Patent Application No. 61/944,788 by Luo et al.,entitled “Techniques for Reporting Channel State Information (CSI) ForAn Unlicensed Radio Frequency Spectrum Band,” filed Feb. 26, 2014,assigned to the assignee hereof, and each of which is herebyincorporated by reference in its entirety.

FIELD OF DISCLOSURE

The present disclosure, for example, relates to wireless communicationsystems, and more particularly to techniques for reporting channel stateinformation (CSI) for an unlicensed radio frequency spectrum band.

BACKGROUND

Wireless communication systems are widely deployed to provide varioustypes of communication content such as voice, video, packet data,messaging, broadcast, and so on. These systems may be multiple-accesssystems capable of supporting communication with multiple users bysharing the available system resources (e.g., time, frequency, andpower). Examples of such multiple-access systems include code-divisionmultiple access (CDMA) systems, time-division multiple access (TDMA)systems, frequency-division multiple access (FDMA) systems, andorthogonal frequency-division multiple access (OFDMA) systems.

By way of example, a wireless multiple-access communication system mayinclude a number of base stations, each simultaneously supportingcommunication for multiple user equipments (UEs; e.g., mobile devices).A base station may communicate with UEs on downlink channels (e.g., fortransmissions from a base station to a UE) and uplink channels (e.g.,for transmissions from a UE to a base station).

Some modes of communication may enable communications with a UE overdifferent radio frequency spectrum bands (e.g., a licensed radiofrequency spectrum band and/or an unlicensed radio frequency spectrumband). With increasing data traffic in cellular networks, the offloadingof at least some data traffic from a licensed radio frequency spectrumband to an unlicensed radio frequency spectrum band may provide acellular operator with opportunities for enhanced data transmissioncapacity.

Prior to gaining access to and transmitting data over the unlicensedradio frequency spectrum band, a transmitting apparatus may, in someexamples, perform a listen before talk (LBT) procedure to gain access tothe unlicensed radio frequency spectrum band. An LBT procedure mayinclude performing a clear channel assessment (CCA) to determine whethera particular channel of the unlicensed radio frequency spectrum band isavailable. When it is determined that the channel of the unlicensedradio frequency spectrum band is not available (e.g., because anotherdevice is already using the channel of the unlicensed radio frequencyspectrum band), a clear channel assessment may be performed for thechannel again at a later time.

When a base station performs a clear channel assessment and gains accessto an unlicensed radio frequency spectrum band, it may assume that a UEwill receive its transmission and respond appropriately. However,situations may arise when a base station does not win contention toaccess the unlicensed radio frequency spectrum band; when a UEincorrectly determines that a clear channel assessment performed by abase station has failed; or when a UE incorrectly determines that aclear channel assessment performed by a base station was successful. Inthese and other situations, a UE may respond to a base station in amanner that is unexpected and potentially ambiguous.

SUMMARY

The present disclosure, for example, relates to one or more techniquesfor reporting CSI for an unlicensed radio frequency spectrum band. Whena clear channel assessment performed by a base station fails for acomponent carrier in an unlicensed radio frequency spectrum band, theone or more signals transmitted to estimate channel state informationfor the component carrier in the unlicensed radio frequency spectrumband may not exist (e.g., a valid measurement subframe may not exist).When a clear channel assessment performed by a base station succeeds fora component carrier in an unlicensed radio frequency spectrum band, buta UE incorrectly determines that it has failed, the UE may assume thatthe one or more signals transmitted to estimate channel stateinformation for the component carrier in the unlicensed radio frequencyspectrum band do not exist (e.g., a valid measurement subframe does notexist). In these and other situations, a UE may not transmit the channelstate information that the base station expects (e.g., the UE maytransmit channel state information corresponding to a differentcomponent carrier; the UE may not transmit current channel stateinformation; or the UE may not transmit channel state information atall. As a result of the scenarios mentioned above, there may beambiguity at a base station regarding whether and/or when channel stateinformation is reported, as well as ambiguity regarding the componentcarrier(s) for which the channel state information is reported.

In a first set of illustrative examples, a method for wirelesscommunication is described. In one example, the method may includereceiving a service via a component carrier, wherein the componentcarrier may be in an unlicensed radio frequency spectrum band, andmeasuring one or more signals transmitted on the component carrier toestimate channel state information of the component carrier in theunlicensed radio frequency spectrum band.

In some examples, the method may include determining that a clearchannel assessment failed for a frame for the component carrier. Inthese examples, and in some cases, the method may include aperiodicallytransmitting the channel state information of the component carrier, theone or more signals being measured during the frame for the componentcarrier. In other cases, the method may include omitting an aperiodictransmission of the channel state information for one or more subframesof the frame for the component carrier.

In some examples, the method may include receiving an aperiodic channelstate information bit associated with the component carrier in theunlicensed radio frequency spectrum band. The aperiodic channel stateinformation bit may indicate whether to aperiodically transmit thechannel state information of the component carrier.

In some examples, the method may include receiving instructions as towhether channel state information for one or more subframes of a framefor the component carrier is to be omitted from an aperiodictransmission of the channel state information. In these examples, thecomponent carrier may include a first component carrier and the methodmay also include receiving the instructions over a second componentcarrier.

In some examples, the method may include periodically transmitting thechannel state information regardless of whether a clear channelassessment failed for a frame for the component carrier.

In some examples, the method may include determining whether a clearchannel assessment failed for a frame for the component carrier, andperiodically transmitting the channel state information. In theseexamples, the measuring one or more signals may include measuring one ormore current signals when the clear channel assessment is determined tohave succeeded for the frame and measuring one or more historic signalswhen the clear channel assessment is determined to have failed for theframe.

In some examples, the method may include periodically transmitting thechannel state information. The channel state information may include anindication used to identify the component carrier associated with thechannel state information. In some examples, the indication mayexplicitly identify the component carrier associated with the channelstate information. In some examples, the indication may include ascrambling pattern associated with the component carrier associated withthe channel state information. The scrambling pattern may include afirst scrambling pattern when the channel state information isassociated with a primary cell, and the scrambling pattern may include asecond scrambling pattern when the channel state information isassociated with a secondary cell. In some examples, the indication mayinclude a rate matching for a multiplexed physical uplink controlchannel (PUCCH) and physical uplink shared channel (PUSCH). In someexamples, the indication may include a resource location of a PUCCH.

In some examples, the method may include determining whether a conditionis met, and periodically transmitting the channel state information. Thechannel state information may include an indication used to identify thecomponent carrier associated with the channel state information when thecondition is met. In some examples, the condition may be a same payloadsize for at least two alternate channel state information transmissions.

In some examples, the method may include determining whether a clearchannel assessment failed for a frame for the component carrier, andperiodically transmitting the channel state information. The channelstate information may include an indication used to identify thecomponent carrier associated with the channel state information when theclear channel assessment is determined to have failed.

In some examples of the method, the determining the clear channelassessment failed may be based at least in part on a channel usagebeacon signal. In some examples of the method, the determining the clearchannel assessment failed may be based at least in part on a referencesignal for a channel state information report. In some examples of themethod, the frame for the component carrier is a downlink frame or anuplink frame.

In a second set of illustrative examples, an apparatus for wirelesscommunication is described. In one example, the apparatus may includemeans for receiving a service via a component carrier, wherein thecomponent carrier may be in an unlicensed radio frequency spectrum band,and means for measuring one or more signals transmitted on the componentcarrier to estimate channel state information of the component carrierin the unlicensed radio frequency spectrum band. In some examples, theapparatus may further include means for implementing one or more aspectsof the method for wireless communication described above with respect tothe first set of illustrative examples.

In a third set of illustrative examples, another apparatus for wirelesscommunication is described. In one example, the apparatus may include aprocessor, memory in electronic communication with the processor, andinstructions stored in the memory. The instructions may be executable bythe processor to receive a service via a component carrier, wherein thecomponent carrier may be in an unlicensed radio frequency spectrum band,and to measure one or more signals transmitted on the component carrierto estimate channel state information of the component carrier in theunlicensed radio frequency spectrum band. In some examples, theinstructions may also be executable by the processor to implement one ormore aspects of the method for wireless communication described abovewith respect to the first set of illustrative examples.

In a fourth set of illustrative examples, a non-transitorycomputer-readable medium storing computer-executable code for wirelesscommunications is described. In one example, the code may be executableby a processor to cause the wireless communication apparatus to receivea service via a component carrier, wherein the component carrier may bein an unlicensed radio frequency spectrum band, and to measure one ormore signals transmitted on the component carrier to estimate channelstate information of the component carrier in the unlicensed radiofrequency spectrum band.

The foregoing has outlined rather broadly the features and technicaladvantages of examples according to the disclosure in order that thedetailed description that follows may be better understood. Additionalfeatures and advantages will be described hereinafter. The conceptionand specific examples disclosed may be readily utilized as a basis formodifying or designing other structures for carrying out the samepurposes of the present disclosure. Such equivalent constructions do notdepart from the spirit and scope of the appended claims. Features whichare believed to be characteristic of the concepts disclosed herein, bothas to their organization and method of operation, together withassociated advantages will be better understood from the followingdescription when considered in connection with the accompanying figures.Each of the figures is provided for the purpose of illustration anddescription only, and not as a definition of the limits of the claims.

BRIEF DESCRIPTION OF THE DRAWINGS

A further understanding of the nature and advantages of the presentinvention may be realized by reference to the following drawings. In theappended figures, similar components or features may have the samereference label. Further, various components of the same type may bedistinguished by following the reference label by a dash and a secondlabel that distinguishes among the similar components. If only the firstreference label is used in the specification, the description isapplicable to any one of the similar components having the same firstreference label irrespective of the second reference label.

FIG. 1 shows a diagram of an example of a wireless communication system,in accordance with various aspects of the present disclosure;

FIG. 2 shows a wireless communication system in which LTE/LTE-A isdeployed under different scenarios using an unlicensed radio frequencyspectrum band, in accordance with various aspects of the presentdisclosure;

FIG. 3 shows examples of a gating interval (or LBT frame) for a cellulardownlink in an unlicensed radio frequency spectrum band, in accordancewith various aspects of the present disclosure;

FIG. 4A shows an example of a wireless communication over an unlicensedradio frequency spectrum band, in accordance with various aspects of thepresent disclosure;

FIG. 4B shows an example of a wireless communication over an unlicensedradio frequency spectrum band, in accordance with various aspects of thepresent disclosure;

FIG. 5 shows example sets of downlink component carriers and uplinkcomponent carriers, in accordance with various aspects of the presentdisclosure;

FIG. 6 shows a block diagram of an apparatus for use in wirelesscommunication, in accordance with various aspects of the presentdisclosure;

FIG. 7 shows a block diagram of an apparatus for use in wirelesscommunication, in accordance with various aspects of the presentdisclosure;

FIG. 8 shows a block diagram of an apparatus for use in wirelesscommunication, in accordance with various aspects of the presentdisclosure;

FIG. 9 shows a block diagram of a UE for use in wireless communication,in accordance with various aspects of the present disclosure;

FIG. 10 is a flow chart illustrating an example of a method for wirelesscommunication, in accordance with various aspects of the presentdisclosure;

FIG. 11 is a flow chart illustrating an example of a method for wirelesscommunication, in accordance with various aspects of the presentdisclosure;

FIG. 12 is a flow chart illustrating an example of a method for wirelesscommunication, in accordance with various aspects of the presentdisclosure;

FIG. 13 is a flow chart illustrating an example of a method for wirelesscommunication, in accordance with various aspects of the presentdisclosure;

FIG. 14 is a flow chart illustrating an example of a method for wirelesscommunication, in accordance with various aspects of the presentdisclosure;

FIG. 15 is a flow chart illustrating an example of a method for wirelesscommunication, in accordance with various aspects of the presentdisclosure;

FIG. 16 is a flow chart illustrating an example of a method for wirelesscommunication, in accordance with various aspects of the presentdisclosure;

FIG. 17 is a flow chart illustrating an example of a method for wirelesscommunication, in accordance with various aspects of the presentdisclosure; and

FIG. 18 is a flow chart illustrating an example of a method for wirelesscommunication, in accordance with various aspects of the presentdisclosure.

DETAILED DESCRIPTION

Techniques are described in which channel state information for anunlicensed radio frequency spectrum band (e.g., a radio frequencyspectrum band for which apparatuses may need to contend for accessbecause the radio frequency spectrum band is available for unlicenseduse, such as a Wi-Fi radio frequency spectrum band) may be reported to abase station in a less ambiguous or non-ambiguous manner.

In some examples, techniques to lessen or eliminate ambiguity in channelstate information reporting may include receiving (e.g., from a basestation) a service via a component carrier. The component carrier may bein an unlicensed radio frequency spectrum band. In some examples, theservice (or one or more other services) may also be received via one ormore additional component carriers in the unlicensed radio frequencyspectrum band and/or one or more component carriers in a licensed radiofrequency spectrum band. One or more signals transmitted on thecomponent carrier may be measured to estimate channel state informationof the component carrier in the unlicensed radio frequency spectrumband. The channel state information may then be transmitted (e.g., tothe base station) in a manner that enables the channel state informationto be understood (e.g., ambiguity in the nature of the channel stateinformation may be lessened or eliminated). Techniques for lessening orremoving ambiguity from channel state information may include, forexample, transmitting the channel state information regardless ofsuccessful clear channel assessment to contend for access to a componentcarrier for a gating interval (e.g., a downlink frame); enabling a basestation to configure one or more reporting options (e.g., whether a UEwill transmit the channel state information regardless of successfulclear channel assessment to contend for access to a component carrierfor a gating interval; when channel state information is to be reported,etc.); transmitting the channel state information with an indicationused to identify the component carrier associated with the channel stateinformation. These and other techniques are described in greater detailwith reference to FIGS. 5-8 and 10-18.

Techniques described herein may be used for various wirelesscommunications systems such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, andother systems. The terms “system” and “network” are often usedinterchangeably. A CDMA system may implement a radio technology such asCDMA2000, Universal Terrestrial Radio Access (UTRA), etc. CDMA2000covers IS-2000, IS-95, and IS-856 standards. IS-2000 Releases 0 and Aare commonly referred to as CDMA2000 1×, 1×, etc. IS-856 (TIA-856) iscommonly referred to as CDMA2000 1×EV-DO, High Rate Packet Data (HRPD),etc. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. ATDMA system may implement a radio technology such as Global System forMobile Communications (GSM). An OFDMA system may implement a radiotechnology such as Ultra Mobile Broadband (UMB), Evolved UTRA (E-UTRA),IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDM™, etc.UTRA and E-UTRA are part of Universal Mobile Telecommunication System(UMTS). 3GPP Long Term Evolution (LTE) and LTE-Advanced (LTE-A) are newreleases of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A, andGSM are described in documents from an organization named “3rdGeneration Partnership Project” (3GPP). CDMA2000 and UMB are describedin documents from an organization named “3rd Generation PartnershipProject 2” (3GPP2). The techniques described herein may be used for thesystems and radio technologies mentioned above as well as other systemsand radio technologies. The description below, however, describes an LTEsystem for purposes of example, and LTE terminology is used in much ofthe description below, although the techniques are applicable beyond LTEapplications.

The following description provides examples, and is not limiting of thescope, applicability, or examples set forth in the claims. Changes maybe made in the function and arrangement of elements discussed withoutdeparting from the spirit and scope of the disclosure. Various examplesmay omit, substitute, or add various procedures or components asappropriate. For instance, the methods described may be performed in anorder different from that described, and various steps may be added,omitted, or combined. Also, features described with respect to certainexamples may be combined in other examples.

FIG. 1 shows a diagram of an example of a wireless communication system100, in accordance with various aspects of the present disclosure. Thewireless communication system 100 may include base stations (or cells)105, UEs 115, and a core network 130. The base stations 105 maycommunicate with the UEs 115 under the control of a base stationcontroller (not shown), which may be part of the core network 130 or thebase stations 105 in various examples. The base stations 105 maycommunicate control information and/or user data with the core network130 through backhaul links 132. Backhaul links 132 may be wired backhaullinks (e.g., copper, fiber, etc.) and/or wireless backhaul links (e.g.,microwave, etc.). In some examples, the base stations 105 maycommunicate, either directly or indirectly, with each other overbackhaul links 134, which may be wired or wireless communication links.The wireless communication system 100 may support operation on multiplecarriers (waveform signals of different frequencies). Multi-carriertransmitters can transmit modulated signals simultaneously on themultiple carriers. For example, each communication link 125 may be amulti-carrier signal modulated according to the various radiotechnologies described above. Each modulated signal may be sent on adifferent carrier and may carry control information (e.g., referencesignals, control channels, etc.), overhead information, data, etc.

The base stations 105 may wirelessly communicate with the UEs 115 viaone or more base station antennas. Each of the base stations 105 mayprovide communication coverage for a respective coverage area 110. Insome examples, a base station 105 may be referred to as an access point,a base transceiver station (BTS), a radio base station, a radiotransceiver, a basic service set (BSS), an extended service set (ESS), aNodeB, an evolved NodeB (eNB), a Home NodeB, a Home eNodeB, a wirelesslocal area network (WLAN) access point, a Wi-Fi node or some othersuitable terminology. The coverage area 110 for a base station 105 maybe divided into sectors making up only a portion of the coverage area.The wireless communication system 100 may include base stations 105 ofdifferent types (e.g., macro, micro, and/or pico base stations). Thebase stations 105 may also utilize different radio technologies, such ascellular and/or WLAN radio access technologies (RAT). The base stations105 may be associated with the same or different access networks oroperator deployments. The coverage areas of different base stations 105,including the coverage areas of the same or different types of basestations 105, utilizing the same or different radio technologies, and/orbelonging to the same or different access networks, may overlap.

The UEs 115 may be dispersed throughout the wireless communicationsystem 100. A UE 115 may also be referred to by those skilled in the artas a mobile device, a mobile station, a subscriber station, a mobileunit, a subscriber unit, a wireless unit, a remote unit, a wirelessdevice, a wireless communication device, a remote device, a mobilesubscriber station, an access terminal, a mobile terminal, a wirelessterminal, a remote terminal, a handset, a user agent, a mobile client, aclient, or some other suitable terminology. A UE 115 may be a cellularphone, a personal digital assistant (PDA), a wireless modem, a wirelesscommunication device, a handheld device, a tablet computer, a laptopcomputer, a cordless phone, a wearable item such as a watch or glasses,a wireless local loop (WLL) station, or the like. A UE 115 may be ableto communicate with macro base stations, pico base stations, femto basestations, relay base stations, and the like. A UE 115 may also be ableto communicate over different types of access networks, such as cellularor other wireless wide area networks (WWANs), or WLANs. In some modes ofcommunication with a UE 115, communication may be conducted over aplurality of communication links 125 or channels, with each channelusing a component carrier between the UE 115 and one of a number ofcells (e.g., serving cells, which cells may in some cases be operated bythe same or different base stations 105).

Each component carrier may be provided over a licensed radio frequencyspectrum band or an unlicensed radio frequency spectrum band, and a setof component carriers used in a particular mode of communication may allbe received (e.g., at a UE 115) over a licensed radio frequency spectrumband, all be received (e.g., at a UE 115) over an unlicensed radiofrequency spectrum band, or be received (e.g., at a UE 115) over acombination of a licensed radio frequency spectrum band and anunlicensed radio frequency spectrum band.

The communication links 125 shown in wireless communication system 100may include uplink channels (using component carriers) for carryinguplink (UL) communications (e.g., transmissions from a UE 115 to a basestation 105) and/or downlink channels (using component carriers) forcarrying downlink (DL) communications (e.g., transmissions from a basestation 105 to a UE 115). The UL communications or transmissions mayalso be called reverse link communications or transmissions, while theDL communications or transmissions may also be called forward linkcommunications or transmissions. The downlink communications and/oruplink communications may be made using a licensed radio frequencyspectrum band, an unlicensed radio frequency spectrum band, or both.

In some examples, the wireless communication system 100 may be orinclude an LTE/LTE-A network. In LTE/LTE-A networks, the terms evolvedNode B (eNB) may be generally used to describe individual ones or groupsof the base stations 105. The wireless communication system 100 may be aHeterogeneous LTE/LTE-A network in which different types of eNBs providecoverage for various geographical regions. For example, each eNB mayprovide communication coverage for a macro cell, a pico cell, a femtocell, and/or other type of cell. A macro cell may generally cover arelatively large geographic area (e.g., several kilometers in radius)and may allow unrestricted access by UEs 115 having servicesubscriptions with the network provider. A pico cell may generally covera relatively smaller geographic area and may allow unrestricted accessby UEs 115 with service subscriptions with the network provider. A femtocell may also generally cover a relatively small geographic area (e.g.,a home) and, in addition to unrestricted access, may also providerestricted access by UEs 115 having an association with the femto cell(e.g., UEs 115 in a closed subscriber group (CSG), UEs 115 for users inthe home, and the like). An eNB for a macro cell may be referred to as amacro eNB. An eNB for a pico cell may be referred to as a pico eNB. And,an eNB for a femto cell may be referred to as a femto eNB or a home eNB.An eNB may support one or multiple (e.g., two, three, four, and thelike) cells.

The wireless communication system 100 according to an LTE/LTE-A networkarchitecture may be referred to as an Evolved Packet System (EPS). AnEPS may include one or more UEs 115, an Evolved UMTS Terrestrial RadioAccess Network (E-UTRAN), an Evolved Packet Core (EPC) (e.g., corenetwork 130), a Home Subscriber Server (HSS), and an Operator's InternetProtocol (IP) Services. The EPS may interconnect with other accessnetworks using other RATs. For example, the EPS may interconnect with aUTRAN-based network and/or a CDMA-based network via one or more ServingGPRS Support Nodes (SGSNs). To support mobility of UEs 115 and/or loadbalancing, the EPS may support handover of UEs 115 between a source eNB(or base station 105) and a target eNB (or base station 105). The EPSmay support intra-RAT handover between eNBs and/or base stations 105 ofthe same RAT (e.g., other E-UTRAN networks), and inter-RAT handoversbetween eNBs and/or base stations 105 of different RATs (e.g., E-UTRANto CDMA, etc.). The EPS may provide packet-switched services, however,as those skilled in the art will readily appreciate, the variousconcepts presented throughout this disclosure may be extended tonetworks providing circuit-switched services.

The E-UTRAN may include eNBs and may provide user plane and controlplane protocol terminations toward the UEs 115. The eNBs and/or basestations 105 may be connected to other eNBs and/or base stations 105 viabackhaul link 134 (e.g., an X2 interface and/or the like). The eNBsand/or base stations 105 may provide access points to the EPC (e.g., thecore network 130) for the UEs 115. The eNBs and/or base stations 105 maybe connected by backhaul link 132 (e.g., an S1 interface and/or thelike) to the EPC. Logical nodes within the EPC may include one or moreMobility Management Entities (MMEs), one or more Serving Gateways, andone or more Packet Data Network (PDN) Gateways (not shown). Generally,the MME may provide bearer and connection management. All user IPpackets may be transferred through the Serving Gateway, which itself maybe connected to the PDN Gateway. The PDN Gateway may provide UE IPaddress allocation as well as other functions. The PDN Gateway may beconnected to IP networks and/or the Operator's IP Services. Theselogical nodes may be implemented in separate physical nodes or one ormore logical nodes may be combined in a single physical node. The IPNetworks/Operator's IP Services may include the Internet, an Intranet,an IP Multimedia Subsystem (IMS), and/or a Packet-Switched (PS)Streaming Service (PSS).

UEs 115 and eNBs or base stations 105 may be configured tocollaboratively communicate through, for example, Multiple InputMultiple Output (MIMO), Coordinated Multi-Point (CoMP), or otherschemes. MIMO techniques use multiple antennas on a base station 105and/or multiple antennas on a UE 115 to take advantage of multipathenvironments to transmit multiple data streams. CoMP includes techniquesfor dynamic coordination of transmission and reception by a number ofeNBs and/or base stations 105 to improve overall transmission qualityfor UEs 115, as well as to increase network and spectrum utilization.Generally, CoMP techniques may utilize backhaul links 132 and/or 134 forcommunication between base stations 105 to coordinate control plane anduser plane communications for the UEs 115.

The communication networks that may accommodate some of the variousdisclosed techniques may be packet-based networks that operate accordingto a layered protocol stack. In the user plane, communications at thebearer or Packet Data Convergence Protocol (PDCP) layer may be IP-based.A Radio Link Control (RLC) layer may perform packet segmentation andreassembly to communicate over logical channels. A Medium Access Control(MAC) layer may perform priority handling and multiplexing of logicalchannels into transport channels. The MAC layer may also use hybridautomatic repeat request (HARQ) techniques to provide retransmission atthe MAC layer to ensure reliable data transmission. In the controlplane, the Radio Resource Control (RRC) protocol layer may provideestablishment, configuration, and maintenance of an RRC connectionbetween the UE and the network used for the user plane data. At thePhysical layer, the transport channels may be mapped to physicalchannels.

The downlink physical channels may include at least one of a physicaldownlink control channel (PDCCH), a physical HARQ indicator channel(PHICH), and a physical downlink shared channel (PDSCH). The uplinkphysical channels may include at least one of a physical uplink controlchannel PUCCH and a physical uplink shared channel PUSCH. The PDCCH maycarry downlink control information (DCI), which may indicate datatransmissions for UEs on the PDSCH as well as provide UL resource grantsto UEs for the PUSCH. The UE may transmit control information in thePUCCH on the assigned resource blocks in the control section. The UE maytransmit only data or both data and control information in the PUSCH onthe assigned resource blocks in the data section.

LTE/LTE-A utilizes orthogonal frequency division multiple-access (OFDMA)on the downlink and single-carrier frequency division multiple-access(SC-FDMA) on the uplink. An OFDMA and/or SC-FDMA carrier may bepartitioned into multiple (K) orthogonal subcarriers, which are alsocommonly referred to as tones, bins, or the like. Each subcarrier may bemodulated with data. The spacing between adjacent subcarriers may befixed, and the total number of subcarriers (K) may be dependent on thesystem bandwidth. For example, K may be equal to 72, 180, 300, 600, 900,or 1200 with a subcarrier spacing of 15 kilohertz (KHz) for acorresponding system bandwidth (with guard band) of 1.4, 3, 5, 10, 15,or 20 megahertz (MHz), respectively. The system bandwidth may also bepartitioned into sub-bands. For example, a sub-band may cover 1.08 MHz,and there may be 1, 2, 4, 8 or 16 sub-bands.

In some examples of the wireless communication system 100, LTE/LTE-A maybe deployed under different scenarios using an unlicensed radiofrequency spectrum band. The deployment scenarios may include asupplemental downlink mode in which LTE/LTE-A downlink communications ina licensed radio frequency spectrum band may be offloaded to anunlicensed radio frequency spectrum band, a carrier aggregation mode inwhich both LTE/LTE-A downlink and uplink communications may be offloadedfrom a licensed radio frequency spectrum band to an unlicensed radiofrequency spectrum band, and a standalone mode in which LTE/LTE-Adownlink and uplink communications between an eNB and/or base stationand a UE may take place in an unlicensed radio frequency spectrum band.Base stations 105 as well as UEs 115 may support one or more of these orsimilar modes of operation. OFDMA waveforms may be used in thecommunication links 125 for LTE/LTE-A downlink communications in thelicensed radio frequency spectrum band and/or the unlicensed radiofrequency spectrum band, while OFDMA, SC-FDMA and/or resource blockinterleaved FDMA waveforms may be used in the communication links 125for LTE/LTE-A uplink communications in the licensed radio frequencyspectrum band and/or unlicensed radio frequency spectrum band.

FIG. 2 shows a wireless communication system 200 in which LTE/LTE-A isdeployed under different scenarios using an unlicensed radio frequencyspectrum band, in accordance with various aspects of the presentdisclosure. More specifically, FIG. 2 illustrates examples of asupplemental downlink mode, a carrier aggregation mode, and a standalonemode in which LTE/LTE-A is deployed using an unlicensed radio frequencyspectrum band. The wireless communication system 200 may be an exampleof portions of the wireless communication system 100 described withreference to FIG. 1. Moreover, a first base station 205 and a secondbase station 205-a may be examples of aspects of one or more of the basestations 105 described with reference to FIG. 1, while a first UE 215, asecond UE 215-a, a third UE 215-b, and a fourth UE 215-c may be examplesof aspects of one or more of the UEs 115 described with reference toFIG. 1.

In the example of a supplemental downlink mode in the wirelesscommunication system 200, the first base station 205 may transmit OFDMAwaveforms to the first UE 215 using a downlink channel 220. The downlinkchannel 220 may be associated with a frequency F1 in an unlicensed radiofrequency spectrum band. The first base station 205 may transmit OFDMAwaveforms to the first UE 215 using a first bidirectional link 225 andmay receive SC-FDMA waveforms from the first UE 215 using the firstbidirectional link 225. The first bidirectional link 225 may beassociated with a frequency F4 in a licensed radio frequency spectrumband. The downlink channel 220 in the unlicensed radio frequencyspectrum band and the first bidirectional link 225 in the licensed radiofrequency spectrum band may operate concurrently. The downlink channel220 may provide a downlink capacity offload for the first base station205. In some examples, the downlink channel 220 may be used for unicastservices (e.g., addressed to one UE) or for multicast services (e.g.,addressed to several UEs). This scenario may occur with any serviceprovider (e.g., a mobile network operator (MNO)) that uses a licensedradio frequency spectrum band and needs to relieve some of the trafficand/or signaling congestion.

In one example of a carrier aggregation mode in the wirelesscommunication system 200, the first base station 205 may transmit OFDMAwaveforms to the second UE 215-a using a second bidirectional link 230and may receive OFDMA waveforms, SC-FDMA waveforms, and/or resourceblock interleaved FDMA waveforms from the second UE 215-a using thesecond bidirectional link 230. The second bidirectional link 230 may beassociated with the frequency F1 in the unlicensed radio frequencyspectrum band. The first base station 205 may also transmit OFDMAwaveforms to the second UE 215-a using a third bidirectional link 235and may receive SC-FDMA waveforms from the second UE 215-a using thethird bidirectional link 235. The third bidirectional link 235 may beassociated with a frequency F2 in a licensed radio frequency spectrumband. The second bidirectional link 230 may provide a downlink anduplink capacity offload for the first base station 205. Like thesupplemental downlink described above, this scenario may occur with anyservice provider (e.g., MNO) that uses a licensed radio frequencyspectrum and needs to relieve some of the traffic and/or signalingcongestion.

In another example of a carrier aggregation mode in the wirelesscommunication system 200, the first base station 205 may transmit OFDMAwaveforms to the third UE 215-b using a fourth bidirectional link 240and may receive OFDMA waveforms, SC-FDMA waveforms, and/or resourceblock interleaved waveforms from the third UE 215-b using the fourthbidirectional link 240. The fourth bidirectional link 240 may beassociated with a frequency F3 in the unlicensed radio frequencyspectrum band. The first base station 205 may also transmit OFDMAwaveforms to the third UE 215-b using a fifth bidirectional link 245 andmay receive SC-FDMA waveforms from the third UE 215-b using the fifthbidirectional link 245. The fifth bidirectional link 245 may beassociated with the frequency F2 in the licensed radio frequencyspectrum band. The fourth bidirectional link 240 may provide a downlinkand uplink capacity offload for the first base station 205. This exampleand those provided above are presented for illustrative purposes andthere may be other similar modes of operation or deployment scenariosthat combine LTE/LTE-A in a licensed radio frequency spectrum band andan unlicensed radio frequency spectrum band for capacity offload.

As described above, one type of service provider that may benefit fromthe capacity offload offered by using LTE/LTE-A in an unlicensed radiofrequency spectrum band is a traditional MNO having access rights to anLTE/LTE-A licensed radio frequency spectrum band. For these serviceproviders, an operational example may include a bootstrapped mode (e.g.,supplemental downlink, carrier aggregation) that uses the LTE/LTE-Aprimary component carrier (PCC) on the licensed radio frequency spectrumband and at least one secondary component carrier (SCC) on theunlicensed radio frequency spectrum band.

In the carrier aggregation mode, data and control may, for example, becommunicated in the licensed radio frequency spectrum band (e.g., viafirst bidirectional link 225, third bidirectional link 235, and fifthbidirectional link 245) while data may, for example, be communicated inthe unlicensed radio frequency spectrum band (e.g., via secondbidirectional link 230 and fourth bidirectional link 240). The carrieraggregation mechanisms supported when using an unlicensed radiofrequency spectrum band may fall under a hybrid frequency divisionduplexing-time division duplexing (FDD-TDD) carrier aggregation or aTDD-TDD carrier aggregation with different symmetry across componentcarriers.

In one example of a standalone mode in the wireless communication system200, the second base station 205-a may transmit OFDMA waveforms to thefourth UE 215-c using a bidirectional link 250 and may receive OFDMAwaveforms, SC-FDMA waveforms, and/or resource block interleaved FDMAwaveforms from the fourth UE 215-c using the bidirectional link 250. Thebidirectional link 250 may be associated with the frequency F3 in anunlicensed radio frequency spectrum band. The standalone mode may beused in non-traditional wireless access scenarios, such as in-stadiumaccess (e.g., unicast, multicast). An example of a type of serviceprovider for this mode of operation may be a stadium owner, cablecompany, event host, hotel, enterprise, or large corporation that doesnot have access to a licensed radio frequency spectrum band.

In some examples, a transmitting apparatus such as one of the basestations 105 and/or 205 described with reference to FIGS. 1 and/or 2,and/or one of the UEs 115 and/or 215 described with reference to FIGS. 1and/or 2, may use a gating interval to gain access to a channel of anunlicensed radio frequency spectrum band (e.g., to a physical channel ofthe unlicensed radio frequency spectrum band). The gating interval maydefine the application of a contention-based protocol, such as an LBTprotocol based on the LBT protocol specified in ETSI (EN 301 893). Whenusing a gating interval that defines the application of an LBT protocol,the gating interval may indicate when a transmitting apparatus needs toperform a CCA. The outcome of the CCA may indicate to the transmittingdevice whether a channel of an unlicensed radio frequency spectrum bandis available or in use for the gating interval (also referred to as anLBT frame). When a CCA indicates that the channel is available (e.g.,“clear” for use) for a corresponding LBT frame, the transmittingapparatus may reserve and/or use the channel of the unlicensed radiofrequency spectrum band during part or all of the LBT frame. When theCCA indicates that the channel is not available (e.g., that the channelis in use or reserved by another apparatus), the transmitting apparatusmay be prevented from using the channel during the LBT frame.

In some cases, it may be useful for a transmitting apparatus to generatea gating interval on a periodic basis and synchronize at least oneboundary of the gating interval with at least one boundary of a periodicframe structure. For example, it may be useful to generate a periodicgating interval for a cellular downlink in an unlicensed radio frequencyspectrum band, and to synchronize at least one boundary of the periodicgating interval with at least one boundary of a periodic frame structure(e.g., a periodic LTE/LTE-A radio frame structure) associated with thecellular downlink. Examples of such synchronization are shown in FIG. 3.

FIG. 3 shows examples 300 of a gating interval (or LBT frame) for acellular downlink in an unlicensed radio frequency spectrum band, inaccordance with various aspects of the present disclosure. The firstgating interval 305, the second gating interval 315, and/or the thirdgating interval 325 may be used as a periodic gating interval by an eNBthat supports transmissions over the unlicensed radio frequency spectrumband. Examples of such an eNB may include the base stations 105 and/or205 described with reference to FIGS. 1 and/or 2. The first gatinginterval 305, the second gating interval 315, and/or the third gatinginterval 325 may be used with the wireless communication system 100and/or 200 described with reference to FIGS. 1 and/or 2.

By way of example, the duration of a first gating interval 305 is shownto be equal to (or approximately equal to) a duration of an LTE/LTE-Aradio frame 310 of a periodic frame structure associated with a cellulardownlink. In some examples, “approximately equal” means the duration ofthe first gating interval 305 is within a cyclic prefix (CP) duration ofthe duration of the periodic frame structure.

At least one boundary of the first gating interval 305 may besynchronized with at least one boundary of the periodic frame structurethat includes the LTE/LTE-A radio frames N−1 to N+1. In some cases, thefirst gating interval 305 may have boundaries that are aligned with theframe boundaries of the periodic frame structure. In other cases, thefirst gating interval 305 may have boundaries that are synchronizedwith, but offset from, the frame boundaries of the periodic framestructure. For example, the boundaries of the first gating interval 305may be aligned with subframe boundaries of the periodic frame structure,or with subframe midpoint boundaries (e.g., the midpoints of particularsubframes) of the periodic frame structure.

In some cases, the periodic frame structure may include LTE/LTE-A radioframes N−1 to N+1. Each LTE/LTE-A radio frame 310 may have a durationoften milliseconds, for example, and the first gating interval 305 mayalso have a duration often milliseconds. In these cases, the boundariesof the first gating interval 305 may be synchronized with the boundaries(e.g., frame boundaries, subframe boundaries, or subframe midpointboundaries) of one of the LTE/LTE-A radio frames (e.g., the LTE/LTE-Aradio frame (N)).

By way of example, the durations of a second gating interval 315 and athird gating interval 325 are shown to be sub-multiples of (orapproximate sub-multiples of) the duration of the periodic framestructure associated with the cellular downlink. In some examples, an“approximate sub-multiple of” means the duration of the second gatinginterval 315 and/or the third gating interval 325 is within a cyclicprefix (CP) duration of the duration of a sub-multiple of (e.g., half orone-tenth) the periodic frame structure. For example, the second gatinginterval 315 may have a duration of five milliseconds and the thirdgating interval 325 may have a duration of two milliseconds. The secondgating interval 315 or the third gating interval 325 may be advantageousover the first gating interval 305 because of its shorter duration mayfacilitate more frequent sharing of an unlicensed radio frequencyspectrum band.

FIG. 4A shows an example 400 of a wireless communication 410 over anunlicensed radio frequency spectrum band, in accordance with variousaspects of the present disclosure. A TDD frame 415, which may correspondto an LBT gating interval, may have a duration of 10 milliseconds andinclude a number of downlink subframes 420, a number of uplink subframes425, and two types of special subframes, an S subframe 430 and an S′subframe 435. The S subframe 430 may provide a transition betweendownlink subframes 420 and uplink subframes 425, while the S′ subframe535 may provide a transition between uplink subframes 425 and downlinksubframes 420. During the S′ subframe 435, a downlink clear channelassessment (DCCA) 440 may be performed by one or more base stations,such as one or more of the base stations 105 and/or 205 described withreference to FIGS. 1 and/or 2, to reserve, for a period of time, thechannel over which the wireless communication 410 occurs. Following asuccessful DCCA 440 by a base station, the base station may transmit achannel usage beacon signal (CUBS) 445 to provide an indication to otherbase stations and/or apparatuses that the base station has reserved thechannel.

The S′ subframe 435 may include 14 OFDM symbols, numbered 0 through 13in FIG. 4A. A first portion of the S′ subframe 435, symbols 0 through 5in this example, may be used by base stations as a silent DL period,which may be required for compatibility with LTE/LTE-A communicationstandards. Thus, a base station may not transmit data during the silentDL period, although a UE may transmit some amount of uplink data duringthe silent DL period. A second portion of the S′ subframe 435 may beused for a DCCA 440. In the example 400, the S′ subframe 435 includesseven DCCA slots, included in symbols 6 through 12. Use of the DCCAslots by different network operators may be coordinated to provide moreefficient system operation. In some examples, in order to determinewhich of the seven possible DCCA slots to use to perform a DCCAprocedure, a base station 105 may evaluate a mapping-function of theform:

-   -   F_(D)(GroupID, t)ϵ{1,2,3,4,5,6,7}        where GroupID is a “deployment group-id” assigned to the base        station 105, and t is the LBT frame number corresponding to a        gating interval or frame for which DCCA is performed.

FIG. 4B shows an example 450 of a wireless communication 455 over anunlicensed radio frequency spectrum band, in accordance with variousaspects of the present disclosure. A TDD frame 415, which may correspondto the LBT frame period of FIG. 4A, and may correspond to an LBT fixedframe period, may include a number of downlink subframes 420, a numberof uplink subframes 425, and two types of special subframes (e.g., an Ssubframe 530 and an S′ subframe 435. As discussed above, the S subframe430 may provide a transition between downlink subframes 420 and uplinksubframes 425, while the S′ subframe 435 may provide a transitionbetween uplink subframes 425 and downlink subframes 420. During the Ssubframe 430, an uplink CCA (UCCA) 565 may be performed by one or moreUEs, such as one or more of the UEs 115 and/or 215 described above withreference to FIGS. 1 and/or 2, to reserve, for a period of time, thechannel over which the wireless communication 455 occurs. Following asuccessful UCCA 465 by a UE, the UE may transmit a channel usage beaconsignal (CUBS) 470 to provide an indication to other UEs and/orapparatuses that the UE has reserved the channel.

The S subframe 430 may include 14 OFDM symbols, numbered 0 through 13 inFIG. 4B. A first portion of the S subframe 430, symbols 0 through 3 inthis example, may be used as a downlink pilot time slot (DwPTS) 475, anda second portion of the S subframe 430 may be used as a guard period(GP) 480. A third portion of the S subframe 430 may be used for UCCA465. In the example 450, the S subframe 430 includes seven U-LBT slots,included in symbols 6 through 12. Use of the U-LBT slots by differentUEs may be coordinated to provide more efficient system operation. Insome examples, in order to determine which of the seven possible UCCAslots to use to perform a UCCA, a UE may evaluate a mapping-function ofthe form:

-   -   F_(U)(GroupID, t)ϵ{1,2,3,4,5,6,7}        where GroupID is a “deployment group-id” assigned to the UE, and        t is the LBT frame number corresponding to a frame for which a        UCCA is performed.

The mapping function for a DCCA and/or a UCCA may be constructed basedon different criteria, depending on whether the mapping function willhave an orthogonalization or a non-orthogonalization property. Inexamples with orthogonal LBT access, the mapping function may have anorthogonalization property according to:

-   -   F_(D/U)(x, t)≠F_(D/U)(y, t)    -   GroupID x, yϵ{1,2,3,4,5,6,7}        for all time t, whenever x≠y represent different group-ids. In        this case, base stations and/or UEs with different group-ids may        perform CCAs during non-overlapping LBT time intervals. In the        absence of interference, the base station or UE with the        group-id which maps to an earlier LBT time slot may secure the        channel for a period of time. According to various deployments,        the mapping-function is fair, in the sense that across different        time indices t, the mapping {F_(D/U)(x, t), t=1, 2, 3, . . . }        varies such that different group-ids have an equal chance of        mapping to an earlier LBT time slot (and hence secure the        channel in the absence of other interference) over a suitably        long interval of time.

All base stations and UEs deployed by the same networkoperator/service-provider may be assigned the same group-id, so thatthey do not preempt each other in the contention process. This allowsfull frequency reuse among base stations and UEs of the same deployment,which may lead to enhanced system throughput. Base stations and/or UEsof different deployments may be assigned different group-ids, so thatwith orthogonal CCA slot mapping, access to the channel is mutuallyexclusive.

In examples with non-orthogonal, or overlapping, CCA slot access, themapping function may allow more than seven group ids. In somesituations, for example, it may be useful to support more than sevendeployment group-ids, in which case it is not possible to maintain theorthogonality property of CCA slot mapping functions. In such cases, itmay be desirable to reduce the frequency of collision between any twogroup-ids. In some examples, non-orthogonal CCA slot mapping sequencesmay also be used to provide fair channel access among deploymentswithout tight coordination on LBT opportunities. One example of anon-orthogonal CCA slot mapping sequence is given by:

-   -   F_(D/U)(x, t)=R_(1,7)(x, t)    -   GroupID xϵ{1, 2, . . . 2¹⁶}        where R_(1,7)(x,t) is a pseudo-random number generator between 1        and 7 chosen independently for GroupID x. In this case, there        could be potential collisions between base stations and/or UEs        of different GroupID's in the same LBT frame t.

Thus, LBT time slots may be selected according to the noted mappingfunctions and used for D-LBT 540 and/or U-LBT 565.

Some modes of communication with a UE may require communication over aplurality of channels (i.e., component carriers), with each channelbeing established between the UE and one of a number of cells usingdifferent component carriers (e.g., serving cells, which in some casesmay be different base stations). In some examples, two or more cells mayuse different carrier frequencies or component carriers, as might befound in a carrier aggregation and/or dual-connectivity (e.g.,multiflow) mode of communication. In other examples, two or more cellsmay be of a same carrier frequency (e.g., component carrier), as mightbe found in a coordinated multipoint (CoMP) mode of communication.Regardless, each component carrier may be used over a licensed basedradio frequency spectrum band and/or an unlicensed radio frequencyspectrum band, and a set of component carriers involved in a particularmode of communication may all be received over the licensed radiofrequency spectrum band, all be received over an unlicensed radiofrequency spectrum band, or be received over a combination of thelicensed radio frequency spectrum band and the unlicensed radiofrequency spectrum band. To establish communication using a componentcarrier over the unlicensed radio frequency spectrum band, a CCA may beperformed to contend for access to the unlicensed radio frequencyspectrum band. When the CCA is successful, the component carrier may beused for communication in the unlicensed radio frequency spectrum band.When the LBT procedure fails, the component carrier may not be used.

FIG. 5 shows example sets 500 of downlink component carriers 505 anduplink component carriers 510, in accordance with various aspects of thepresent disclosure. More particularly, and by way of example, FIG. 5shows five DL component carriers (CCs) 505 and five uplink UL CCs 510.The DL CCs 505 include a DL primary component carrier (DL PCC) 505-a, afirst DL secondary component carrier (DL SCC) 505-b, a second DL SCC505-c, a third DL SCC 505-d, and a fourth DL SCC 505-e. Similarly, theUL CCs 510 include a UL PCC 510-a, a first UL SCC 510-b, a second UL SCC510-c, a third UL SCC 510-d, and a fourth UL SCC 510-e. The UL PCC 510-amay, for a network such as an LTE/LTE-A network, carry a PUCCH; and eachof the UL PCC 510-a, the first UL SCC 510-b, the second UL SCC 510-c,the third UL SCC 510-d, and the fourth UL SCC 510-e may carry a PUSCH.Uplink control information such as acknowledgements andnon-acknowledgements (ACKs/NAKs), CSI, and/or scheduling request (SR)control information may, in some examples, be transmitted on the PUCCH.

In some examples, each of the DL PCC 505-a, the first DL SCC 505-b, thesecond DL SCC 505-c, the third DL SCC 505-d, and the fourth DL SCC 505-emay be mapped to the UL PCC 510-a for purposes of reporting uplinkcontrol information for a first cell corresponding to the DL PCC 505-a,a second cell corresponding to the first DL SCC 505-b, a third cellcorresponding to the second DL SCC 505-c, a fourth cell corresponding tothe third DL SCC 505-d, and a fifth cell corresponding the fourth DL SCC505-e. To reduce the overhead of the PUCCH carried on the UL PCC 510-a,the PUCCH may be configured such that a resource (e.g., a sharedresource, such as one or more OFDM symbols) in an uplink subframe of theUL PCC 510-a is used to report uplink control information for each ofthe first cell, the second cell, the third cell, the fourth cell, andthe fifth cell. A conflict for the resource in the uplink subframe maytherefore exist. To resolve the conflict, reporting of the uplinkcontrol information for each of the first cell, the second cell, thethird cell, the fourth cell, and the fifth cell may be prioritized suchthat uplink control information for one of the first cell, the secondcell, the third cell, the fourth cell, and the fifth cell is transmittedduring a particular instance of the resource.

Periodic uplink control information reporting and/or aperiodic uplinkcontrol information reporting may be supported in a system in which dataand control information is transmitted from a plurality of cells (e.g.,using different component carriers) to a UE over a set of DL CCs such asthe DL CCs 505, and transmitted from the UE to one or more of the basestations corresponding to the plurality of cells over a set of UL CCssuch as the UL CCs 510. In an example of periodic uplink controlinformation reporting in a carrier aggregation mode, the reporting ofuplink control information may be prioritized based on priority levelsof reporting types of CSI.

In some examples, the priority levels of the reporting types of CSI mayinclude: a top priority level when a reporting type of CSI includes atleast one of a rank indicator (RI), a precoding type indicator (PTI), ora wideband precoding matrix indicator (PMI) (e.g., a reporting type of3, 5, 6, or 2a); a medium priority level when a reporting type of CSIincludes at least one of a wideband channel quality indication (CQI), ora wideband CQI with PMI (e.g., a reporting type of 2, 2b, 2c, or 4);and/or a low priority level when a reporting type of CSI includes atleast one of a subband CQI, or a subband CQI with PMI (e.g., a reportingtype of 1, 1a). When a priority level of the reporting type of CSI isthe same for two or more cells, priority for reporting uplink controlinformation may be determined based on a comparison of serving cellindices of the conflicting cells. For example, a cell with a lower cellindex may be given a priority over a cell with a higher cell index. Theserving cell indices for a plurality of cells may be configured on aUE-by-UE basis. The same priority rules may be applied regardless ofwhether PUSCH is transmitted.

After prioritizing the reporting of uplink control information for aplurality of cells, the uplink control information for the cellassociated with the highest priority may be reported using the resourcefor which a conflict exists, and the uplink control information for theremaining cells may be discarded.

In an example of aperiodic uplink control information reporting in acarrier aggregation mode, the reporting of uplink control informationmay be prioritized based on the state of a two bit CSI request field, inwhich a “00” state may indicate that no CSI should be reported; a “01”state may indicate that uplink control information for the cell/DL CC505 that is system information block 2 (SIB2)-linked to the UL PCC510-a; and “10” and “11” states may indicate that the prioritization ofthe reporting of uplink control information for a plurality of cells isconfigured by radio resource control (RRC). For the common search space,a “0” state may indicate that no CSI should be reported; and a “1” statemay indicate that the prioritization of the reporting of uplink controlinformation for a plurality of cells is configured by RRC. The RRC mayprioritize reporting for any combination of up to five componentcarriers.

In an example of aperiodic uplink control information reporting in aCoMP mode, for which two or more CSI processes may be defined, with eachCSI process associated with a particular transmission point involved inCoMP, the reporting of uplink control information may be prioritizedbased on the state of a two bit CSI request field, in which a “00” statemay indicate that no CSI should be reported; a “01” state may indicatethat the prioritization of the reporting of uplink control informationfor a plurality of cells is configured by RRC, with the RRC-configuredCSI process limited to a given cell; and “10” and “11” states mayindicate that the prioritization of the reporting of uplink controlinformation for a plurality of cells is configured by RRC. For thecommon search space, a “0” state may indicate that no CSI should bereported; and a “1” state may indicate that the prioritization of thereporting of uplink control information for a plurality of cells isconfigured by RRC. The RRC may prioritize reporting for any combinationof up to five component carriers.

Consider now a set of DL CCs such as the DL CCs 505 shown in FIG. 5. Inone example, a first DL CC, such as the DL PCC 505-a, is transmittedover a licensed radio frequency spectrum band (e.g., a radio frequencyspectrum band for which apparatuses do not contend for access becausethe spectrum band is licensed to particular users for particular uses).A second DL CC, such as the DL SCC 505-b, may be transmitted over anunlicensed radio frequency spectrum band (e.g., a radio frequencyspectrum band for which apparatuses may need to contend for accessbecause the radio frequency spectrum band is available for unlicenseduse, such as a Wi-Fi radio frequency spectrum band). Because a DL PCC is(in some examples) assigned a serving cell index of “0” (i.e., thelowest serving cell index), any time there is a conflict for resourcesbased on priority level of reporting type of CSI, the cell associatedwith the DL PCC 505-a will be given priority. This, combined with thefact that use of an unlicensed radio frequency spectrum band isdependent on contending for access to the unlicensed radio frequencyspectrum band via a successful LBT procedure (and thereforeopportunistic), means that the reporting of uplink control informationfor the cell associated with the DL SCC 505-b may be infrequent or, insome cases, effectively blocked. However, because of the dynamic natureof contending for access to an unlicensed radio frequency spectrum band,uplink control information for a cell that uses a CC over an unlicensedradio frequency spectrum band may be more valuable—especially when thereis a long succession of failed clear channel assessments. Thus, in someexamples, it may be useful to prioritize the reporting of uplink controlinformation, for a shared resource of an uplink subframe, based at leastin part on whether a cell utilizes an unlicensed radio frequencyspectrum band.

When a clear channel assessment performed by a base station fails to wincontention to access a component carrier in an unlicensed radiofrequency spectrum band, the one or more signals transmitted to estimatechannel state information for the component carrier in the unlicensedradio frequency spectrum band may not exist (e.g., a valid measurementsubframe may not exist). In the case of periodic CSI reporting, a UE mayestimate and/or report channel state information based on measurementstaken for a last valid subframe (e.g., measurements for the lastsubframe for which a clear channel assessment performed by the basestation was successful). However, in the case of aperiodic CSIreporting, the event-driven nature of the aperiodic CSI reporting mayrequire the buffering of measurements (or a measurement subframe) forestimating channel state information. Because aperiodic CSI reporting isevent-driven, the measurements taken for a last valid subframe may needto be buffered for an indefinite duration (e.g., until a base stationwins contention to access a component carrier of an unlicensed radiofrequency spectrum band).

When a clear channel assessment performed by a base station succeeds,but a UE incorrectly determines that it has failed, the UE may assumethat the one or more signals transmitted to estimate channel stateinformation for the component carrier in the unlicensed radio frequencyspectrum band do not exist (e.g., a valid measurement subframe does notexist).

In one example, there may be ambiguity at a base station regardingwhether and/or when CSI is reported, as well as ambiguity regarding thecomponent carrier(s) for which the CSI is reported (i.e., there may bemisalignment of the base station with respect to the CSI reporting ofthe UE). This ambiguity may be due to a failure of a clear channelassessment performed by a base station. This ambiguity may also becaused by a UE incorrectly determining that a clear channel assessmentperformed by a base station has succeeded or failed (when, in fact, theclear channel assessment has not succeeded or has not failed). Further,this ambiguity may be the result of a UE reporting different types ofCSI (or no CSI) based on whether a clear channel assessment performed bya base station is determined to have succeeded or failed. Variousmisalignment issues of an eNB with respect to aperiodic CSI reporting ofa UE and periodic CSI reporting of a UE are described below.

As a first example of a misalignment issue of a base station withrespect to aperiodic channel state information reporting, consider a UEthat incorrectly determines that a clear channel assessment failed toaccess a component carrier in an unlicensed radio frequency spectrumband for a downlink frame. Because the UE determines that the clearchannel assessment failed, the UE may omit reporting aperiodic channelstate information associated with the component carrier in theunlicensed radio frequency spectrum band. However, because the clearchannel assessment performed by the base station was successful, thebase station may expect a report of aperiodic channel state information(assuming the base station dynamically requested a report of aperiodicchannel state information). This represents a misalignment issue. As asecond example of a misalignment issue, consider aperiodic channel stateinformation that is reported along with an uplink shared channel(UL-SCH) on a PUSCH. Because the aperiodic channel state information maybe multiplexed with the UL-SCH by splitting available PUSCH resources, abase station may not be able to discern which PUSCH resources areallocated to the aperiodic channel state information and which resourcesare allocated to the UL-SCH. This represents a misalignment issue. Insome cases, the base station may attempt to blindly detect theallocation of resources for the aperiodic channel state information andthe UL-SCH. The blind detection may or may not be successful. As a thirdexample of a misalignment issue, consider a transmission of onlyaperiodic channel state information in the presence of multiplecomponent carriers (e.g., a primary component carrier and one or moresecondary component carriers). A base station may be unable to determinethe number or identity(ies) of component carriers to which the aperiodicchannel state information applies. This represents a misalignment issue.

As a first example of a misalignment issue of a base station withrespect to periodic channel state information reporting, consider a UEthat incorrectly determines that a clear channel assessment failed for adownlink frame for a component carrier in an unlicensed radio frequencyspectrum band. Because the UE determines that the clear channelassessment failed, the UE may omit reporting periodic channel stateinformation or report periodic channel state information for a componentcarrier in a licensed radio frequency spectrum band. However, becausethe clear channel assessment performed by the base station wassuccessful, the base station may expect a report of periodic channelstate information for a component carrier in an unlicensed radiofrequency spectrum band. Although a base station that receives periodicchannel state information from the UE may attempt to blindly detectwhether the periodic channel state information corresponds to acomponent carrier in an unlicensed radio frequency spectrum band or acomponent carrier in a licensed radio frequency spectrum band, the blinddetection may not be successful (e.g., especially when the bitwidth ofthe periodic channel state information for the unlicensed radiofrequency spectrum band and the bitwidth of the periodic channel stateinformation for the licensed radio frequency spectrum band are thesame). This represents a misalignment issue.

FIG. 6 shows a block diagram 600 of an apparatus 605 for use in wirelesscommunication, in accordance with various aspects of the presentdisclosure. In some examples, the apparatus 605 may be an example ofaspects of one or more of the UEs 115 and/or 215 described withreference to FIGS. 1 and/or 2. The apparatus 605 may also be aprocessor. The apparatus 605 may include a receiver module 610, awireless communication management module 620, and/or a transmittermodule 630. Each of these components may be in communication with eachother.

The components of the apparatus 605 may, individually or collectively,be implemented using one or more application-specific integratedcircuits (ASICs) adapted to perform some or all of the applicablefunctions in hardware. Alternatively, the functions may be performed byone or more other processing units (or cores), on one or more integratedcircuits. In other examples, other types of integrated circuits may beused (e.g., Structured/Platform ASICs, Field Programmable Gate Arrays(FPGAs), and other Semi-Custom ICs), which may be programmed in anymanner known in the art. The functions of each unit may also beimplemented, in whole or in part, with instructions embodied in amemory, formatted to be executed by one or more general orapplication-specific processors.

In some examples, the receiver module 610 may include at least one radiofrequency (RF) receiver, such as at least one RF receiver operable toreceive transmissions over a licensed radio frequency spectrum band(e.g., a radio frequency spectrum band for which apparatuses do notcontend for access because the radio frequency spectrum band is licensedto particular users for particular uses) and/or an unlicensed radiofrequency spectrum band (e.g., a radio frequency spectrum band for whichapparatuses may need to contend for access because the radio frequencyspectrum band is available for unlicensed use, such as a Wi-Fi radiofrequency spectrum band and/or another unlicensed radio frequencyspectrum band). In some examples, both the licensed radio frequencyspectrum band and the unlicensed radio frequency spectrum band may beused for LTE/LTE-A communications, as described, for example, withreference to FIGS. 1 and/or 2. The receiver module 610 may be used toreceive various types of data and/or control signals (i.e.,transmissions) over one or more communication links of a wirelesscommunication system, such as one or more communication links of thewireless communication system 100 and/or 200 described with reference toFIGS. 1 and/or 2. The communication links may be established over thelicensed radio frequency spectrum band and/or the unlicensed radiofrequency spectrum band.

In some examples, the transmitter module 630 may include at least one RFtransmitter, such as at least one RF transmitter operable to transmitover the licensed radio frequency spectrum band and/or the unlicensedradio frequency spectrum band. The transmitter module 630 may be used totransmit various types of data and/or control signals (i.e.,transmissions) over one or more communication links of a wirelesscommunication system, such as one or more communication links of thewireless communication system 100 and/or 200 described with reference toFIGS. 1 and/or 2. The communication links may be established over thelicensed radio frequency spectrum band and/or the unlicensed radiofrequency spectrum band.

In some examples, the wireless communication management module 620 maybe configured to receive a service via one or more component carriers,with at least one of the component carriers being in an unlicensed radiofrequency spectrum band. The wireless communication management module620 may also be configured to measure one or more signals associatedwith at least one of the component carriers to estimate channel stateinformation of at least one component carrier in the unlicensed radiofrequency spectrum band. The channel state information may then betransmitted (e.g., to a base station) in a manner that enables thechannel state information to be understood (e.g., in a manner in whichambiguity in the nature of the channel state information may be lessenedor eliminated). Techniques for lessening or removing ambiguity fromchannel state information may include, for example, transmitting thechannel state information even when a clear channel assessment isdetermined to have failed for a downlink frame for a component carrier;enabling a base station to explicitly configure what channel stateinformation is to be transmitted when; or transmitting the channel stateinformation with an indication used to identify the component carrierassociated with the channel state information. These and othertechniques are described in greater detail with reference to FIGS. 7, 8,and 10-18.

FIG. 7 shows a block diagram 700 of an apparatus 705 for use in wirelesscommunication, in accordance with various aspects of the presentdisclosure. In some examples, the apparatus 705 may be an example ofaspects of one or more of the UEs 115 and/or 215 described withreference to FIGS. 1 and/or 2, and/or an example of aspects of theapparatus 605 described with reference to FIG. 6. The apparatus 705 mayalso be a processor. The apparatus 705 may include a receiver module710, a wireless communication management module 720, and/or atransmitter module 730. Each of these components may be in communicationwith each other.

The components of the apparatus 705 may, individually or collectively,be implemented using one or more ASICs adapted to perform some or all ofthe applicable functions in hardware. Alternatively, the functions maybe performed by one or more other processing units (or cores), on one ormore integrated circuits. In other examples, other types of integratedcircuits may be used (e.g., Structured/Platform ASICs, FPGAs, and otherSemi-Custom ICs), which may be programmed in any manner known in theart. The functions of each unit may also be implemented, in whole or inpart, with instructions embodied in a memory, formatted to be executedby one or more general or application-specific processors.

In some examples, the receiver module 710 may include at least one RFreceiver, such as at least one RF receiver operable to receivetransmissions over licensed radio frequency spectrum band (e.g., a radiofrequency spectrum band for which apparatuses do not contend for accessbecause the radio frequency spectrum band is licensed to particularusers for particular uses) and/or an unlicensed radio frequency spectrumband (e.g., a radio frequency spectrum band for which apparatuses mayneed to contend for access because the radio frequency spectrum band isavailable for unlicensed use, such as a Wi-Fi radio frequency spectrumband). In some examples, both the licensed radio frequency spectrum bandand the unlicensed radio frequency spectrum band may be used forLTE/LTE-A communications, as described, for example, with reference toFIGS. 1 and/or 2. The receiver module 710 may in some cases includeseparate receivers for the licensed radio frequency spectrum band andthe unlicensed radio frequency spectrum band. The separate receiversmay, in some examples, take the form of a licensed RF spectrum bandLTE/LTE-A receiver module 712 for communicating over the licensed radiofrequency spectrum band, and an unlicensed RF spectrum band LTE/LTE-Areceiver module 714 for communicating over the unlicensed radiofrequency spectrum band. The receiver module 710, including the licensedRF spectrum band LTE/LTE-A receiver module 712 and/or the unlicensed RFspectrum band LTE/LTE-A receiver module 714, may be used to receivevarious types of data and/or control signals (i.e., transmissions) overone or more communication links of a wireless communication system, suchas one or more communication links of the wireless communication system100 and/or 200 described with reference to FIGS. 1 and/or 2. Thecommunication links may be established over the licensed radio frequencyspectrum band and/or the unlicensed radio frequency spectrum band.

In some examples, the transmitter module 730 may include at least one RFtransmitter, such as at least one RF transmitter operable to transmitover the licensed radio frequency spectrum band and/or the unlicensedradio frequency spectrum band. The transmitter module 730 may in somecases include separate transmitters for the licensed radio frequencyspectrum band and the unlicensed radio frequency spectrum band. Theseparate transmitters may, in some examples, take the form of a licensedRF spectrum band LTE/LTE-A transmitter module 732 for communicating overthe licensed radio frequency spectrum band, and an unlicensed RFspectrum band LTE/LTE-A transmitter module 734 for communicating overthe unlicensed radio frequency spectrum band. The transmitter module730, including the licensed RF spectrum band LTE/LTE-A transmittermodule 732 and/or the unlicensed RF spectrum band LTE/LTE-A transmittermodule 734, may be used to transmit various types of data and/or controlsignals (i.e., transmissions) over one or more communication links of awireless communication system, such as one or more communication linksof the wireless communication system 100 and/or 200 described withreference to FIGS. 1 and/or 2. The communication links may beestablished over the licensed radio frequency spectrum band and/or theunlicensed radio frequency spectrum band.

In some examples, the wireless communication management module 720 maybe an example of one or more aspects of the wireless communicationmanagement module 620 described with reference to FIG. 6. The wirelesscommunication management module 720 may include a component carriermanagement module 735, and/or a component carrier signal measurementmodule 740. Each of these components may be in communication with eachother.

In some examples, the component carrier management module 735 may beused to receive (e.g., from a base station) a service via a componentcarrier. The component carrier may be in an unlicensed radio frequencyspectrum band. In some examples, the service (or one or more otherservices) may be received via one or more additional component carriersin the unlicensed radio frequency spectrum band and/or one or morecomponent carriers in a licensed radio frequency spectrum band.

In some examples, the component carrier signal measurement module 740may be used to measure one or more signals transmitted on the componentcarrier to estimate channel state information of the component carrierin the unlicensed radio frequency spectrum band.

FIG. 8 shows a block diagram 800 of an apparatus 805 for use in wirelesscommunication, in accordance with various aspects of the presentdisclosure. In some examples, the apparatus 805 may be an example ofaspects of one or more of the UEs 115 and/or 215 described withreference to FIGS. 1 and/or 2, and/or an example of aspects of theapparatuses 605 and/or 705 described with reference to FIGS. 6 and/or 7.The apparatus 805 may also be a processor. The apparatus 805 may includea receiver module 810, a wireless communication management module 820,and/or a transmitter module 830. Each of these components may be incommunication with each other.

The components of the apparatus 805 may, individually or collectively,be implemented using one or more ASICs adapted to perform some or all ofthe applicable functions in hardware. Alternatively, the functions maybe performed by one or more other processing units (or cores), on one ormore integrated circuits. In other examples, other types of integratedcircuits may be used (e.g., Structured/Platform ASICs, FPGAs, and otherSemi-Custom ICs), which may be programmed in any manner known in theart. The functions of each unit may also be implemented, in whole or inpart, with instructions embodied in a memory, formatted to be executedby one or more general or application-specific processors.

In some examples, the receiver module 810 may include at least one RFreceiver, such as at least one RF receiver operable to receivetransmissions over licensed radio frequency spectrum band (e.g., a radiofrequency spectrum band for which apparatuses do not contend for accessbecause the radio frequency spectrum band is licensed to particularusers for particular uses) and/or an unlicensed radio frequency spectrumband (e.g., a radio frequency spectrum band for which apparatuses mayneed to contend for access because the radio frequency spectrum band isavailable for unlicensed use, such as a Wi-Fi radio frequency spectrumband). In some examples, both the licensed radio frequency spectrum bandand the unlicensed radio frequency spectrum band may be used forLTE/LTE-A communications, as described, for example, with reference toFIGS. 1 and/or 2. The receiver module 810 may in some cases includeseparate receivers for the licensed radio frequency spectrum band andthe unlicensed radio frequency spectrum band. The separate receiversmay, in some examples, take the form of a licensed RF spectrum bandLTE/LTE-A receiver module 812 for communicating over the licensed radiofrequency spectrum band, and an unlicensed RF spectrum band LTE/LTE-Areceiver module 814 for communicating over the unlicensed radiofrequency spectrum band. The receiver module 810, including the licensedRF spectrum band LTE/LTE-A receiver module 812 and/or the unlicensed RFspectrum band LTE/LTE-A receiver module 814, may be used to receivevarious types of data and/or control signals (i.e., transmissions) overone or more communication links of a wireless communication system, suchas one or more communication links of the wireless communication system100 and/or 200 described with reference to FIGS. 1 and/or 2. Thecommunication links may be established over the licensed radio frequencyspectrum band and/or the unlicensed radio frequency spectrum band.

In some examples, the transmitter module 830 may include at least one RFtransmitter, such as at least one RF transmitter operable to transmitover the licensed radio frequency spectrum band and/or the unlicensedradio frequency spectrum band. The transmitter module 830 may in somecases include separate transmitters for the licensed radio frequencyspectrum band and the unlicensed radio frequency spectrum band. Theseparate transmitters may, in some examples, take the form of a licensedRF spectrum band LTE/LTE-A transmitter module 832 for communicating overthe licensed radio frequency spectrum band, and an unlicensed RFspectrum band LTE/LTE-A transmitter module 834 for communicating overthe unlicensed radio frequency spectrum band. The transmitter module830, including the licensed RF spectrum band LTE/LTE-A transmittermodule 832 and/or the unlicensed RF spectrum band LTE/LTE-A transmittermodule 834, may be used to transmit various types of data and/or controlsignals (i.e., transmissions) over one or more communication links of awireless communication system, such as one or more communication linksof the wireless communication system 100 and/or 200 described withreference to FIGS. 1 and/or 2. The communication links may beestablished over the licensed radio frequency spectrum band and/or theunlicensed radio frequency spectrum band.

In some examples, the wireless communication management module 820 maybe an example of one or more aspects of the wireless communicationmanagement module 620 and/or 720 described with reference to FIGS. 6and/or 7. The wireless communication management module 820 may include aDCCA analysis module 835, a component carrier management module 840, acomponent carrier signal measurement module 845, an aperiodic CSI(A-CSI) reporting module 850, and/or a periodic CSI (P-CSI) reportingmodule 870. Each of these components may be in communication with eachother.

In some examples, the DCCA analysis module 835 may be used to determinewhether a clear channel assessment failed for a downlink frame for acomponent carrier in an unlicensed radio frequency spectrum band. Insome examples, the DCCA analysis module 835 may determine whether theclear channel assessment failed based at least in part on a channelusage beacon signal, a reference signal for a channel state informationreport, and/or other information received for a downlink frame (any orall of which may be received from a base station over the componentcarrier in the unlicensed radio frequency spectrum band).

In some examples, the component carrier management module 840 may beused to receive (e.g., from a base station) a service via a componentcarrier. The component carrier may be in an unlicensed radio frequencyspectrum band. In some examples, the service (or one or more otherservices) may also be received via one or more additional componentcarriers in the unlicensed radio frequency spectrum band and/or one ormore component carriers in a licensed radio frequency spectrum band.

In some examples, the component carrier signal measurement module 845may be used to measure one or more signals transmitted on the at leastone component carrier to estimate channel state information of thecomponent carrier in the unlicensed radio frequency spectrum band.Alternately, or additionally, the component carrier signal measurementmodule 845 may be used to measure one or more signals transmitted on atleast one component carrier in a licensed radio frequency spectrum band.

In some examples, the A-CSI reporting module 850 may be used toaperiodically transmit channel state information (e.g., to a basestation). For example, in a first mode of operation of the apparatus805, the component carrier management module 840 may be used to receive(e.g., from a base station) a service via a component carrier. Thecomponent carrier may be in an unlicensed radio frequency spectrum band.The DCCA analysis module 835 may be used to determine whether a clearchannel assessment failed for a downlink frame for the componentcarrier. Upon determining that the clear channel assessment succeededfor the downlink frame for the component carrier, the component carriersignal measurement module 845 may be used to measure one or more signalstransmitted on the component carrier to estimate channel stateinformation of the component carrier in the unlicensed radio frequencyspectrum band. The A-CSI reporting module 850 may then be used toaperiodically transmit or not transmit the channel state informationaccording to default reporting rules, as described, for example, withreference to FIG. 5. Upon determining that the clear channel assessmentfailed to access a component carrier in the unlicensed radio frequencyspectrum band for the downlink frame, the component carrier signalmeasurement module 845 may be used to 1) retrieve measurements for oneor more historic signals transmitted on the component carrier toestimate channel state information of the component carrier in theunlicensed radio frequency spectrum band (e.g., retrieve measurementsbased on a measuring of one or more historic signals associated with thecomponent carrier to estimate channel state information), or 2) measureone or more current signals transmitted on the component carrier toestimate channel state information of the component carrier in theunlicensed radio frequency spectrum band. The one or more signals may bemeasured during the downlink frame for the component carrier. The A-CSIreporting module 850 and/or A-CSI semi-static configuration module 855may then be used to aperiodically transmit the channel state informationof the component carrier.

The first mode of operation of the apparatus 805 may be useful, in onerespect, because the aperiodic transmission of channel state informationis not dependent on a UE correctly determining whether a clear channelassessment failed. This may provide better alignment between a basestation and a UE that are in communication over a component carrier, butat the expense of higher overhead—especially when a serving cell orcells for a component carrier in an unlicensed radio frequency spectrumband has/have a high probability of failed clear channel assessments. Insome examples, a base station receiving the channel state informationtransmitted by the apparatus 805 may discard channel state informationthat is not useful (e.g., because it corresponds to a clear channelassessment that actually failed).

In a second mode of operation of the apparatus 805, the componentcarrier management module 840 may be used to receive (e.g., from a basestation) a service via a component carrier. The component carrier may bein an unlicensed radio frequency spectrum band. The DCCA analysis module835 may be used to determine whether a clear channel assessment failedfor a downlink frame for the component carrier. Upon determining thatthe clear channel assessment succeeded for the downlink frame for thecomponent carrier, the component carrier signal measurement module 845may be used to measure one or more signals associated with the componentcarrier in the unlicensed radio frequency spectrum band to estimatechannel state information. The A-CSI reporting module 850 and/or A-CSIsemi-static configuration module 855 may then be used to aperiodicallytransmit or not transmit the channel state information according todefault reporting rules, as described, for example, with reference toFIG. 5. Upon determining that the clear channel assessment failed toaccess a component carrier in the unlicensed radio frequency spectrumband for the downlink frame, the component carrier signal measurementmodule 845 may be used to 1) retrieve measurements for one or morehistoric signals transmitted on the component carrier to estimatechannel state information of the component carrier in the unlicensedradio frequency spectrum band (e.g., retrieve measurements based on ameasuring of one or more historic signals associated with the componentcarrier to estimate channel state information), or 2) measure one ormore current signals transmitted on the at least one component carrierto estimate channel state information of the component carrier in theunlicensed radio frequency spectrum band. The one or more signals may bemeasured during the downlink frame for the component carrier. The A-CSIreporting module 850 may then be used to omit an aperiodic transmissionof the channel state information for one or more subframes of thedownlink frame for the component carrier.

In a third mode of operation of the apparatus 805, the component carriermanagement module 840 may be used to receive (e.g., from a base station)a service via a component carrier. The component carrier may be in anunlicensed radio frequency spectrum band. The apparatus 805 may receiveinstructions or indications from a base station to determine whether toreport channel state information associated with the component carrierin the unlicensed radio frequency spectrum band. For example, theinstructions or indications may be provided via a channel stateinformation bit associated with the component carrier in the unlicensedradio frequency spectrum band. The A-CSI reporting bit management module860 may be used to receive an aperiodic channel state information bitassociated with the component carrier in the unlicensed radio frequencyspectrum band. The aperiodic channel state information bit may indicatewhether to aperiodically transmit the channel state information of thecomponent carrier. The aperiodic channel state information bit may beprovided, for example, in a downlink and/or control transmission of aneNB. In some examples, an aperiodic channel state information bit may beprovided for each of a number of component carriers in the unlicensedradio frequency spectrum band. The DCCA analysis module 835 may be usedto determine whether a clear channel assessment failed for a downlinkframe for the component carrier. The component carrier signalmeasurement module 845 may be used to measure one or more signalstransmitted on the at least one component carrier to estimate channelstate information of the component carrier in the unlicensed radiofrequency spectrum band. The A-CSI reporting module 850 may then be usedto aperiodically transmit or not transmit the channel state informationaccording to a state of the aperiodic channel state information bitassociated with the component carrier in the unlicensed radio frequencyspectrum band. For example, the A-CSI reporting module 850 and/or A-CSIreporting bit management module 860 may be used to transmit the channelstate information when the state of the aperiodic channel stateinformation bit is a logic high (e.g., a binary “1”), and not transmitthe channel state information when the state of the aperiodic channelstate information is a logic low (e.g., a binary “0”).

The third mode of operation of the apparatus 805 may be useful, in onerespect, because the aperiodic transmission of channel state informationis not dependent on a UE correctly determining whether a clear channelassessment failed, but is instead based on an explicit indication (e.g.,from a base station) of whether channel state information should betransmitted. This may provide better alignment between a base stationand a UE that are in communication over a component carrier.

In a fourth mode of operation of the apparatus 805, the componentcarrier management module 840 may be used to receive (e.g., from a basestation) a service via a component carrier. The component carrier may bein an unlicensed radio frequency spectrum band. The A-CSI instructionmanagement module 865 may be used to receive instructions as to whichmode of operation to use when reporting channel state informationassociated with a component carrier. The instructions may be provided,for example, in a downlink and/or control transmission of a basestation. In some examples, the instructions may indicate that (or when)channel state information is to be transmitted regardless of whether aclear channel assessment is determined to have failed for a downlinkframe for the component carrier, or that (or when) an aperiodictransmission of channel state information is to be omitted when a clearchannel assessment is determined to have failed for the componentcarrier, or that an aperiodic transmission of channel state informationis to be made or not made based on an instruction or indication (e.g., achannel state information bit) provided by a base station. In someexamples, the component carrier may be a first component carrier and theA-CSI instruction management module 865 may be used to receive theinstructions over a second component carrier. The DCCA analysis module835 may be used to determine whether a clear channel assessment failedfor a downlink frame for the component carrier. The component carriersignal measurement module 845 may be used to measure one or more signalstransmitted on the component carrier to estimate channel stateinformation in the unlicensed radio frequency spectrum band. The A-CSIreporting module 850 may then be used to aperiodically transmit or nottransmit the channel state information according to the instructionsreceived by the A-CSI instruction management module 865.

The fourth mode of operation of the apparatus 805 may be useful, in onerespect, because the aperiodic transmission of channel state informationis configurable. For example, the method for aperiodically transmittingor not transmitting channel state information may be determined by abase station that does or does not want to receive the channel stateinformation when a UE determines that a clear channel assessment failedfor a downlink frame for a component carrier in an unlicensed radiofrequency spectrum band.

In some examples, the P-CSI reporting module 870 may be used toperiodically transmit channel state information (e.g., to a basestation). For example, in a fifth mode of operation of the apparatus805, the component carrier management module 840 may be used to receive(e.g., from a base station) a service via a component carrier. Thecomponent carrier may be in an unlicensed radio frequency spectrum band.The DCCA analysis module 835 may be used to determine whether a clearchannel assessment failed for a downlink frame for the componentcarrier. The component carrier signal measurement module 845 may be usedto measure one or more signals transmitted on the component carrier toestimate channel state information of the component carrier in theunlicensed radio frequency spectrum band. In an example, when a clearchannel assessment to contend for access to a component carrier in anunlicensed radio frequency spectrum band fails for a downlink frame, theP-CSI reporting module 870 and/or P-CSI semi-static configuration module875 may be used to periodically report outdated channel stateinformation (e.g., channel state information associated with a priorsuccessful clear channel assessment to gain access to the componentcarrier in the unlicensed radio frequency spectrum band). The P-CSIreporting module 870 and/or P-CSI semi-static configuration module 875may then be used to periodically transmit the channel state informationregardless of whether a clear channel assessment failed to access acomponent carrier in an unlicensed radio frequency spectrum band for thedownlink frame.

The fifth mode of operation of the apparatus 805 may be useful, in onerespect, because the periodic transmission of channel state informationis not dependent on a UE correctly determining whether a clear channelassessment failed. This may provide better alignment between a basestation and a UE that are in communication over a component carriers.

In a sixth mode of operation of the apparatus 805, the component carriermanagement module 840 may be used to receive (e.g., from a base station)a service via a component carrier. The DCCA analysis module 835 may beused to determine whether a clear channel assessment failed for adownlink frame for the component carrier. Upon determining that theclear channel assessment succeeded for the downlink frame for thecomponent carrier, the component carrier signal measurement module 845may measure one or more current signals transmitted on the componentcarrier to estimate channel state information of the component carrierin the unlicensed radio frequency spectrum band. Upon determining thatthe clear channel assessment failed for the downlink frame for thecomponent carrier, the component carrier signal measurement module 845may be used to 1) retrieve measurements for one or more historic signalstransmitted on the component carrier to estimate channel stateinformation of the component carrier in the unlicensed radio frequencyspectrum band, or 2) measure one or more current signals transmitted onat least one component carrier in a licensed radio frequency spectrumband to estimate channel state information. The P-CSI reporting module870 and/or P-CSI semi-static configuration module 875 may then be usedto periodically transmit or not transmit the channel state informationaccording to default reporting rules, as described, for example, withreference to FIG. 5.

The sixth mode of operation of the apparatus 805 may be useful, in onerespect, because the periodic transmission of channel state informationis not dependent on a UE correctly determining whether a clear channelassessment failed. However, a base station receiving the channel stateinformation transmitted by the P-CSI reporting module 870 and/or P-CSIsemi-static configuration module 875 may need to blindly detect whichtype of channel state information it receives from a UE. If a basestation cannot detect which type of channel state information itreceives from a UE, the base station may have to discard the channelstate information.

In a seventh mode of operation of the apparatus 805, the componentcarrier management module 840 may be used to receive (e.g., from a basestation) a service via a component carrier. The component carrier may bein an unlicensed radio frequency spectrum band. The DCCA analysis module835 may be used to determine whether a clear channel assessment failedfor a downlink frame for the component carrier. The component carriersignal measurement module 845 may be used to measure one or more signalstransmitted on the component carrier to estimate channel stateinformation of the component carrier in the unlicensed radio frequencyspectrum band. The P-CSI reporting module 870 and/or P-CSI semi-staticconfiguration module 875 may then be used to periodically transmit thechannel state information. In some examples, the channel stateinformation may include an indication used to identify the componentcarrier associated with the channel state information, regardless ofwhether the clear channel assessment failed for the downlink frame forthe component carrier. In other examples, the channel state informationmay include the indication used to identify the component carrierassociated with the channel state information when the clear channelassessment analyzed by the DCCA analysis module is determined to havefailed.

In some examples, the indication used to identify the component carrierassociated with the channel state information may explicitly identifythe component carrier associated with the channel state information.

In some examples, the indication used to identify the component carrierassociated with the channel state information may implicitly identifythe component carrier associated with the channel state information. Forexample, the indication used to identify the component carrierassociated with the channel state information may include a scramblingpattern (e.g., a scrambling code) associated with the component carrierassociated with the channel state information. In one particularexample, the scrambling pattern may include a first scrambling patternwhen the channel state information is associated with a primary cell,and the scrambling pattern may include a second scrambling pattern whenthe channel state information is associated with a secondary cell.

In another example, the indication used to identify the componentcarrier associated with the channel state information may include a ratematching for a multiplexed PUCCH and PUSCH and/or a PUCCH resourcelocation. For example, a first rate matching may be used when thechannel state information is associated with a primary cell, and asecond rate matching may be used when the channel state information isassociated with a secondary cell.

The seventh mode of operation of the apparatus 805 may be useful, in onerespect, because channel state information is periodically transmittedwith an indication that removes ambiguity regarding the componentcarrier to which it pertains.

In an eighth mode of operation of the apparatus 805, the componentcarrier management module 840 may be used to receive (e.g., from a basestation) a service via a component carrier. The component carrier may bein an unlicensed radio frequency spectrum band. The DCCA analysis module835 may be used to determine whether a clear channel assessment failedfor a downlink frame for the component carrier. The component carriersignal measurement module 845 may be used to measure one or more signalstransmitted on the component carrier to estimate channel stateinformation of the component carrier in the unlicensed radio frequencyspectrum band. The P-CSI condition monitoring module 885 may be used todetermine whether a condition is met. In one example, the condition mayinclude a same payload size for at least two alternate channel stateinformation transmissions. A same payload size may exist, for example,when a channel state information transmission for the component carrieruses the same transmission mode and the same number of transmit antennasand/or receive antennas as a channel state information transmission forat least one other component carrier. Upon determining that thecondition is not met, the P-CSI reporting module 870 and/or P-CSIcondition monitoring module 885 may periodically transmit the channelstate information according to default reporting rules, as described,for example, with reference to FIG. 5. Upon determining that thecondition is met, the P-CSI reporting module 870 and/or P-CSI conditionmonitoring module 885 may be used to periodically transmit the channelstate information with an indication used to identify the componentcarrier associated with the channel state information. In this manner,ambiguity for a base station that receives the channel state informationtransmitted by the apparatus 805 may be lessened or mitigated. Inparticular, when the channel state information for at least a firstcomponent carrier and the channel state information transmission for atleast a second component carrier have the same payload size, theapparatus 805 may transmit channel state information with an indicationused to identify the component carrier associated with the channel stateinformation.

The eighth mode of operation of the apparatus 805 may be useful, in onerespect, because channel state information may be periodicallytransmitted with an indication that removes ambiguity regarding thecomponent carrier to which it pertains.

FIG. 9 shows a block diagram 900 of a UE 915 for use in wirelesscommunication, in accordance with various aspects of the presentdisclosure. The UE 915 may have various configurations and may beincluded or be part of a personal computer (e.g., a laptop computer, anetbook computer, a tablet computer, etc.), a cellular telephone, a PDA,a digital video recorder (DVR), an internet appliance, a gaming console,an e-reader, etc. The UE 915 may, in some examples, have an internalpower supply (not shown), such as a small battery, to facilitate mobileoperation. In some examples, the UE 915 may be an example of aspects ofone or more of the UEs 115 and/or 215 described with reference to FIGS.1 and/or 2, and/or aspects of the apparatus 605, 705, and/or 805described with reference to FIGS. 6, 7, and/or 8. The UE 915 may beconfigured to implement at least some of the UE and/or apparatusfeatures and functions described with reference to FIGS. 1, 2, 3, 4, 5B,6, 7, and/or 8.

The UE 915 may include a UE processor module 910, a UE memory module920, at least one UE transceiver module (represented by UE transceivermodule(s) 930), at least one UE antenna (represented by UE antenna(s)940), and/or a UE wireless communication management module 960. Each ofthese components may be in communication with each other, directly orindirectly, over one or more buses 935.

The UE memory module 920 may include random access memory (RAM) and/orread-only memory (ROM). The UE memory module 920 may storecomputer-readable, computer-executable code 925 containing instructionsthat are configured to, when executed, cause the UE processor module 910to perform various functions described herein related to wirelesscommunication and/or channel state information reporting. Alternatively,the code 925 may not be directly executable by the UE processor module910 but be configured to cause the UE 915 (e.g., when compiled andexecuted) to perform various of the functions described herein.

The UE processor module 910 may include an intelligent hardware device,e.g., a CPU, a microcontroller, an ASIC, etc.). The UE processor module910 may process information received through the UE transceivermodule(s) 930 and/or information to be sent to the UE transceivermodule(s) 930 for transmission through the UE antenna(s) 940. The UEprocessor module 910 may handle, alone or in connection with the UEwireless communication management module 960, various aspects ofcommunicating over (or managing communications over) a first radiofrequency spectrum band (e.g., a radio frequency spectrum band for whichapparatuses do not contend for access because the radio frequencyspectrum band is licensed to particular users for particular uses, suchas a licensed radio frequency spectrum band usable for LTE/LTE-Acommunications) and/or a second radio frequency spectrum band (e.g., aradio frequency spectrum band for which apparatuses may need to contendfor access because the radio frequency spectrum band is available forunlicensed use, such as a Wi-Fi radio frequency spectrum band and/oranother unlicensed radio frequency spectrum band usable for LTE/LTE-Acommunications).

The UE transceiver module(s) 930 may include a modem configured tomodulate packets and provide the modulated packets to the UE antenna(s)940 for transmission, and to demodulate packets received from the UEantenna(s) 940. The UE transceiver module(s) 930 may, in some examples,be implemented as one or more UE transmitter modules and one or moreseparate UE receiver modules. The UE transceiver module(s) 930 maysupport communications in the first radio frequency spectrum band and/orthe second radio frequency spectrum band. The UE transceiver module(s)930 may be configured to communicate bi-directionally, via the UEantenna(s) 940, with one or more of the base stations 105 and/or 205described with reference to FIGS. 1 and/or 2. While the UE 915 mayinclude a single UE antenna, there may be examples in which the UE 915may include multiple UE antennas 940.

The UE state module 950 may be used, for example, to manage transitionsof the UE 915 between a radio resource control (RRC) idle state and anRRC connected state, and may be in communication with other componentsof the UE 915, directly or indirectly, over the one or more buses 935.The UE state module 950, or portions of it, may include a processor,and/or some or all of the functions of the UE state module 950 may beperformed by the UE processor module 910 and/or in connection with theUE processor module 910.

The UE wireless communication management module 960 may be configured toperform and/or control some or all of the features and/or functionsdescribed with reference to FIGS. 1, 2, 3, 4A, 4B, 5, 6, 7, and/or 8related to wireless communication over the first radio frequencyspectrum band and/or the second radio frequency spectrum band and/orchannel state information reporting. For example, the UE wirelesscommunication management module 960 may be configured to support asupplemental downlink mode, a carrier aggregation mode, and/or astandalone mode using the first radio frequency spectrum band and/or thesecond radio frequency spectrum band. The UE wireless communicationmanagement module 960 may also be configured to support a reporting ofaperiodic channel state information and/or periodic channel stateinformation. The UE wireless communication management module 960 mayinclude a UE licensed LTE/LTE-A module 965 configured to handleLTE/LTE-A communications in the first radio frequency spectrum band, anda UE LTE/LTE-A module for unlicensed spectrum 970 configured to handleLTE/LTE-A communications in the second radio frequency spectrum. The UEwireless communication management module 960, or portions of it, mayinclude a processor, and/or some or all of the functions of the UEwireless communication management module 960 may be performed by the UEprocessor module 910 and/or in connection with the UE processor module910. In some examples, the UE wireless communication management module960 may be an example of the wireless communication management module620, 720, and/or 820 described with reference to FIGS. 6, 7, and/or 8.

FIG. 10 is a flow chart illustrating an example of a method 1000 forwireless communication, in accordance with various aspects of thepresent disclosure. For clarity, the method 1000 is described below withreference to aspects of one or more of the UEs 115, 215, and/or 915described with reference to FIGS. 1, 2, and/or 9, and/or aspects of oneor more of the apparatuses 605, 705, and/or 805 described with referenceto FIGS. 6, 7, and/or 8. In some examples, a UE and/or apparatus mayexecute one or more sets of codes to control the functional elements ofthe base station and/or apparatus to perform the functions describedbelow.

At block 1005, the method 1000 may include receiving (e.g., from a basestation) a service via a component carrier. The component carrier may bein an unlicensed radio frequency spectrum band (e.g., a radio frequencyspectrum band for which apparatuses may need to contend for accessbecause the radio frequency spectrum band is available for unlicenseduse, such as a Wi-Fi radio frequency spectrum band). In some examples,the service (or one or more other services) may be received via one ormore additional component carriers in the unlicensed radio frequencyspectrum band and/or one or more component carriers in a licensed radiofrequency spectrum band (e.g., a radio frequency spectrum band for whichapparatuses do not contend for access because the spectrum band islicensed to particular users for particular uses). The operation(s) atblock 1005 may be performed using the wireless communication managementmodule 620, 720, 820, and/or 960 described with reference to FIGS. 6, 7,8, and/or 9, and/or the component carrier management module 735 and/or840 described with reference to FIGS. 7 and/or 8.

At block 1010, the method 1000 may include measuring one or more signalstransmitted on the component carrier to estimate channel stateinformation of the component carrier in the unlicensed radio frequencyspectrum band. The operation(s) at block 1010 may be performed using thewireless communication management module 620, 720, 820, and/or 960described with reference to FIGS. 6, 7, 8, and/or 9, and/or thecomponent carrier signal measurement module 740 and/or 845 describedwith reference to FIGS. 7 and/or 8.

Thus, the method 1000 may provide for wireless communication. It shouldbe noted that the method 1000 is just one implementation and that theoperations of the method 1000 may be rearranged or otherwise modifiedsuch that other implementations are possible.

FIG. 11 is a flow chart illustrating an example of a method 1100 forwireless communication, in accordance with various aspects of thepresent disclosure. For clarity, the method 1100 is described below withreference to aspects of one or more of the UEs 115, 215, and/or 915described with reference to FIGS. 1, 2, and/or 9, and/or aspects of oneor more of the apparatuses 605, 705, and/or 805 described with referenceto FIGS. 6, 7, and/or 8. In some examples, a UE and/or apparatus mayexecute one or more sets of codes to control the functional elements ofthe base station and/or apparatus to perform the functions describedbelow.

At block 1105, the method 1100 may include receiving (e.g., from a basestation) a service via a component carrier. The component carrier may bein an unlicensed radio frequency spectrum band (e.g., a radio frequencyspectrum band for which apparatuses may need to contend for accessbecause the radio frequency spectrum band is available for unlicenseduse, such as a Wi-Fi radio frequency spectrum band). In some examples,the service (or one or more other services) may also be received via oneor more additional component carriers in the unlicensed radio frequencyspectrum band and/or one or more component carriers in a licensed radiofrequency spectrum band (e.g., a radio frequency spectrum band for whichapparatuses do not contend for access because the spectrum band islicensed to particular users for particular uses). The operation(s) atblock 1105 may be performed using the wireless communication managementmodule 620, 720, 820, and/or 960 described with reference to FIGS. 6, 7,8, and/or 9, and/or the component carrier management module 735 and/or840 described with reference to FIGS. 7 and/or 8.

At block 1110, the method 1100 may include determining whether a clearchannel assessment failed for a frame for the component carrier. Theframe for the component carrier may be a downlink frame or an uplinkframe. In some examples, the determining whether the clear channelassessment failed may be based at least in part on a channel usagebeacon signal, a reference signal for a channel state informationreport, and/or other information received for the frame (any or all ofwhich may be received from a base station over the component carrier inthe unlicensed radio frequency spectrum band). The operation(s) at block1110 may be performed using the wireless communication management module620, 720, 820, and/or 960 described with reference to FIGS. 6, 7, 8,and/or 9, and/or the DCCA analysis module 835 described with referenceto FIG. 8.

Upon determining that the clear channel assessment succeeded for theframe for the component carrier, and at block 1115, the method 1100 mayinclude measuring one or more signals transmitted on the componentcarrier to estimate channel state information of the component carrierin the unlicensed radio frequency spectrum band. In some examples, theoperation(s) at block 1115 may occur before the operation(s) at block1110. The operation(s) at block 1110 may be performed using the wirelesscommunication management module 620, 720, 820, and/or 960 described withreference to FIGS. 6, 7, 8, and/or 9, and/or the component carriersignal measurement module 740 and/or 845 described with reference toFIGS. 7 and/or 8.

At block 1120, the method 1100 may include aperiodically transmitting ornot transmitting the channel state information according to defaultreporting rules, as described, for example, with reference to FIG. 5.The operation(s) at block 1120 may be performed using the wirelesscommunication management module 620, 720, 820, and/or 960 described withreference to FIGS. 6, 7, 8, and/or 9, and/or the A-CSI reporting module850 described with reference to FIG. 8.

Upon determining that the clear channel assessment failed for the framefor the at least one component carrier, and at block 1125, the method1100 may include 1) retrieving measurements for one or more historicsignals transmitted on the component carrier to estimate channel stateinformation of the component carrier in the unlicensed radio frequencyspectrum band (e.g., retrieving measurements based on a measuring of oneor more historic signals associated with the component carrier toestimate channel state information), or 2) measuring one or more currentsignals transmitted on the component carrier to estimate channel stateinformation of the component carrier in the unlicensed radio frequencyspectrum band. In some examples, the operation(s) at block 1125 mayoccur before the operation(s) at block 1110. The operation(s) at block1125 may be performed using the wireless communication management module620, 720, 820, and/or 960 described with reference to FIGS. 6, 7, 8,and/or 9, and/or the component carrier signal measurement module 740and/or 845 described with reference to FIGS. 7 and/or 8.

At block 1130, the method 1100 may include aperiodically transmittingthe channel state information of the component carrier. The operation(s)at block 1130 may be performed using the wireless communicationmanagement module 620, 720, 820, and/or 960 described with reference toFIGS. 6, 7, 8, and/or 9, and/or the A-CSI reporting module 850 and/orA-CSI semi-static configuration module 855 described with reference toFIG. 8.

The method 1100 may be useful, in one respect, because the aperiodictransmission of channel state information is not dependent on a UEcorrectly determining whether a clear channel assessment failed. Thismay provide better alignment between a base station and a UE that are incommunication over a component carrier, but at the expense of higheroverhead—especially when a serving cell or cells for a component carrierin an unlicensed radio frequency spectrum band has/have a highprobability of failed clear channel assessments. In some examples, abase station receiving the channel state information transmitted atblock 1130 may discard channel state information that is not useful(e.g., because it corresponds to a clear channel assessment thatactually failed).

Thus, the method 1100 may provide for wireless communication. It shouldbe noted that the method 1100 is just one implementation and that theoperations of the method 1100 may be rearranged or otherwise modifiedsuch that other implementations are possible.

FIG. 12 is a flow chart illustrating an example of a method 1200 forwireless communication, in accordance with various aspects of thepresent disclosure. For clarity, the method 1200 is described below withreference to aspects of one or more of the UEs 115, 215, and/or 915described with reference to FIGS. 1, 2, and/or 9, and/or aspects of oneor more of the apparatuses 605, 705, and/or 805 described with referenceto FIGS. 6, 7, and/or 8. In some examples, a UE and/or apparatus mayexecute one or more sets of codes to control the functional elements ofthe base station and/or apparatus to perform the functions describedbelow.

At block 1205, the method 1200 may include receiving (e.g., from a basestation) a service via a component carrier. The component carrier may bein an unlicensed radio frequency spectrum band (e.g., a radio frequencyspectrum band for which apparatuses may need to contend for accessbecause the radio frequency spectrum band is available for unlicenseduse, such as a Wi-Fi radio frequency spectrum band). In some examples,the service (or one or more other services) may also be received via oneor more additional component carriers in the unlicensed radio frequencyspectrum band and/or one or more component carriers in a licensed radiofrequency spectrum band (e.g., a radio frequency spectrum band for whichapparatuses do not contend for access because the spectrum band islicensed to particular users for particular uses). The operation(s) atblock 1205 may be performed using the wireless communication managementmodule 620, 720, 820, and/or 960 described with reference to FIGS. 6, 7,8, and/or 9, and/or the component carrier management module 735 and/or840 described with reference to FIGS. 7 and/or 8.

At block 1210, the method 1200 may include determining whether a clearchannel assessment failed for a frame for the component carrier. Theframe for the component carrier may be an uplink frame or a downlinkframe. In some examples, the determining whether the clear channelassessment failed may be based at least in part on a channel usagebeacon signal, a reference signal for a channel state informationreport, and/or other information received for the frame (any or all ofwhich may be received from a base station over the component carrier inthe unlicensed radio frequency spectrum band). The operation(s) at block1210 may be performed using the wireless communication management module620, 720, 820, and/or 960 described with reference to FIGS. 6, 7, 8,and/or 9, and/or the DCCA analysis module 835 described with referenceto FIG. 8.

Upon determining that the clear channel assessment succeeded for theframe for the component carrier, and at block 1215, the method 1200 mayinclude measuring one or more signals transmitted on the componentcarrier to estimate channel state information of the component carrierin the unlicensed radio frequency spectrum band. In some examples, theoperation(s) at block 1215 may occur before the operation(s) at block1210. The operation(s) at block 1215 may be performed using the wirelesscommunication management module 620, 720, 820, and/or 960 described withreference to FIGS. 6, 7, 8, and/or 9, and/or the component carriersignal measurement module 740 and/or 845 described with reference toFIGS. 7 and/or 8.

At block 1220, the method 1200 may include aperiodically transmitting ornot transmitting the channel state information according to defaultreporting rules, as described, for example, with reference to FIG. 5.The operation(s) at block 1220 may be performed using the wirelesscommunication management module 620, 720, 820, and/or 960 described withreference to FIGS. 6, 7, 8, and/or 9, and/or the A-CSI reporting module850 described with reference to FIG. 8.

Upon determining that the clear channel assessment failed for the framefor the at least one component carrier, and at block 1225, the method1200 may include 1) retrieving measurements for one or more historicsignals transmitted on the component carrier to estimate channel stateinformation of the component carrier in the unlicensed radio frequencyspectrum band (e.g., retrieving measurements based on a measuring of oneor more historic signals associated with the component carrier toestimate channel state information), or 2) measuring one or more currentsignals transmitted on the component carrier to estimate channel stateinformation of the component carrier in the unlicensed radio frequencyspectrum band. In some examples, the operation(s) at block 1225 mayoccur before the operation(s) at block 1210. The operation(s) at block1225 may be performed using the wireless communication management module620, 720, 820, and/or 960 described with reference to FIGS. 6, 7, 8,and/or 9, and/or the component carrier signal measurement module 740and/or 845 described with reference to FIGS. 7 and/or 8.

At block 1230, the method 1200 may include omitting an aperiodictransmission of the channel state information for one or more subframesof the frame for the component carrier. The operation(s) at block 1230may be performed using the wireless communication management module 620,720, 820, and/or 960 described with reference to FIGS. 6, 7, 8, and/or9, and/or the A-CSI reporting module 850 and/or A-CSI semi-staticconfiguration module 855 described with reference to FIG. 8.

Thus, the method 1200 may provide for wireless communication. It shouldbe noted that the method 1200 is just one implementation and that theoperations of the method 1200 may be rearranged or otherwise modifiedsuch that other implementations are possible.

FIG. 13 is a flow chart illustrating an example of a method 1300 forwireless communication, in accordance with various aspects of thepresent disclosure. For clarity, the method 1300 is described below withreference to aspects of one or more of the UEs 115, 215, and/or 915described with reference to FIGS. 1, 2, and/or 9, and/or aspects of oneor more of the apparatuses 605, 705, and/or 805 described with referenceto FIGS. 6, 7, and/or 8. In some examples, a UE and/or apparatus mayexecute one or more sets of codes to control the functional elements ofthe base station and/or apparatus to perform the functions describedbelow.

At block 1305, the method 1300 may include receiving (e.g., from a basestation) a service via a component carrier. The component carrier may bein an unlicensed radio frequency spectrum band (e.g., a radio frequencyspectrum band for which apparatuses may need to contend for accessbecause the radio frequency spectrum band is available for unlicenseduse, such as a Wi-Fi radio frequency spectrum band). In some examples,the service (or one or more other services) may also be received via oneor more additional component carriers in the unlicensed radio frequencyspectrum band and/or one or more component carriers in a licensed radiofrequency spectrum band (e.g., a radio frequency spectrum band for whichapparatuses do not contend for access because the spectrum band islicensed to particular users for particular uses). The operation(s) atblock 1305 may be performed using the wireless communication managementmodule 620, 720, 820, and/or 960 described with reference to FIGS. 6, 7,8, and/or 9, and/or the component carrier management module 735 and/or840 described with reference to FIGS. 7 and/or 8.

At block 1310, the method 1300 may include receiving an aperiodicchannel state information bit associated with the component carrier inthe unlicensed radio frequency spectrum band. The aperiodic channelstate information bit may indicate whether to aperiodically transmit thechannel state information of the component carrier. The aperiodicchannel state information bit may be provided, for example, in adownlink and/or control transmission of a base station. In someexamples, an aperiodic channel state information bit may be provided foreach of a number of component carriers in the unlicensed radio frequencyspectrum band. The operation(s) at block 1310 may be performed using thewireless communication management module 620, 720, 820, and/or 960described with reference to FIGS. 6, 7, 8, and/or 9, and/or the A-CSIreporting module 850 and/or A-CSI reporting bit management module 860described with reference to FIG. 8.

At block 1315, the method 1300 may include determining whether a clearchannel assessment failed for a frame for the component carrier. In someexamples, the determining whether the clear channel assessment failedmay be based at least in part on a channel usage beacon signal, areference signal for a channel state information report, and/or otherinformation received for the frame (any or all of which may be receivedfrom a base station over the component carrier in the unlicensed radiofrequency spectrum band). In some instances, the frame for the componentcarrier may be a downlink frame. In some instances, the frame for thecomponent carrier may be an uplink frame. The operation(s) at block 1315may be performed using the wireless communication management module 620,720, 820, and/or 960 described with reference to FIGS. 6, 7, 8, and/or9, and/or the DCCA analysis module 835 described with reference to FIG.8.

At block 1320, the method 1300 may include measuring one or more signalstransmitted on the component carrier to estimate channel stateinformation of the component carrier in the unlicensed radio frequencyspectrum band. In some examples, the operation(s) at block 1320 mayoccur before the operation(s) at block 1315. The operation(s) at block1320 may be performed using the wireless communication management module620, 720, 820, and/or 960 described with reference to FIGS. 6, 7, 8,and/or 9, and/or the component carrier signal measurement module 740and/or 845 described with reference to FIGS. 7 and/or 8.

At block 1325, the method 1300 may include aperiodically transmitting ornot transmitting the channel state information according to a state ofthe aperiodic channel state information bit associated with thecomponent carrier in the unlicensed radio frequency spectrum band. Forexample, the channel state information may be transmitted when the stateof the aperiodic channel state information bit is a logic “1,” and nottransmitted when the state of the aperiodic channel state informationbit is a logic “0.” The operation(s) at block 1325 may be performedusing the wireless communication management module 620, 720, 820, and/or960 described with reference to FIGS. 6, 7, 8, and/or 9, and/or theA-CSI reporting module 850 and/or A-CSI reporting bit management module860 described with reference to FIG. 8.

The method 1300 may be useful, in one respect, because the aperiodictransmission of channel state information is not dependent on a UEcorrectly determining whether a clear channel assessment failed, but isinstead based on an explicit indication (e.g., from a base station) ofwhether channel state information should be transmitted. This mayprovide better alignment between a base station and a UE that are incommunication over a component carrier.

Thus, the method 1300 may provide for wireless communication. It shouldbe noted that the method 1300 is just one implementation and that theoperations of the method 1300 may be rearranged or otherwise modifiedsuch that other implementations are possible.

FIG. 14 is a flow chart illustrating an example of a method 1400 forwireless communication, in accordance with various aspects of thepresent disclosure. For clarity, the method 1400 is described below withreference to aspects of one or more of the UEs 115, 215, and/or 915described with reference to FIGS. 1, 2, and/or 9, and/or aspects of oneor more of the apparatuses 605, 705, and/or 805 described with referenceto FIGS. 6, 7, and/or 8. In some examples, a UE and/or apparatus mayexecute one or more sets of codes to control the functional elements ofthe base station and/or apparatus to perform the functions describedbelow.

At block 1405, the method 1400 may include receiving (e.g., from a basestation) a service via a component carrier. The component carrier may bein an unlicensed radio frequency spectrum band (e.g., a radio frequencyspectrum band for which apparatuses may need to contend for accessbecause the radio frequency spectrum band is available for unlicenseduse, such as a Wi-Fi radio frequency spectrum band). In some examples,the service (or one or more other services) may also be received via oneor more additional component carriers in the unlicensed radio frequencyspectrum band and/or one or more component carriers in a licensed radiofrequency spectrum band (e.g., a radio frequency spectrum band for whichapparatuses do not contend for access because the spectrum band islicensed to particular users for particular uses). The operation(s) atblock 1405 may be performed using the wireless communication managementmodule 620, 720, 820, and/or 960 described with reference to FIGS. 6, 7,8, and/or 9, and/or the component carrier management module 735 and/or840 described with reference to FIGS. 7 and/or 8.

At block 1410, the method 1400 may include receiving instructions as towhether channel state information for one or more subframes of a frame(e.g., a downlink frame or an uplink frame) for the component carrier isto be omitted from an aperiodic transmission of the channel stateinformation. The instructions may be provided, for example, in adownlink and/or control transmission of a base station. In someexamples, the instructions may indicate that (or when) channel stateinformation is to be transmitted regardless of whether a clear channelassessment is determined to have failed for a frame for the componentcarrier, or that (or when) an aperiodic transmission of channel stateinformation is to be omitted when a clear channel assessment isdetermined to have failed for the component carrier. In some examples,the component carrier may be a first component carrier and theinstructions may be received over a second component carrier. The firstcomponent carrier and the second component carrier may be associatedwith the same or different base stations. The operation(s) at block 1410may be performed using the wireless communication management module 620,720, 820, and/or 960 described with reference to FIGS. 6, 7, 8, and/or9, and/or the A-CSI reporting module 850 and/or A-CSI instructionmanagement module 865 described with reference to FIG. 8.

At block 1415, the method 1400 may include determining whether a clearchannel assessment failed for the frame for the component carrier. Insome examples, the determining whether the clear channel assessmentfailed may be based at least in part on a channel usage beacon signal, areference signal for a channel state information report, and/or otherinformation received for the frame (any or all of which may be receivedfrom a base station over the component carrier in the unlicensed radiofrequency spectrum band). The operation(s) at block 1415 may beperformed using the wireless communication management module 620, 720,820, and/or 960 described with reference to FIGS. 6, 7, 8, and/or 9,and/or the DCCA analysis module 835 described with reference to FIG. 8.

At block 1420, the method 1400 may include measuring one or more signalstransmitted on the component carrier in the unlicensed radio frequencyspectrum band to estimate channel state information of the componentcarrier in the unlicensed radio frequency spectrum band. In someexamples, the operation(s) at block 1420 may occur before theoperation(s) at block 1415. The operation(s) at block 1420 may beperformed using the wireless communication management module 620, 720,820, and/or 960 described with reference to FIGS. 6, 7, 8, and/or 9,and/or the component carrier signal measurement module 740 and/or 845described with reference to FIGS. 7 and/or 8.

At block 1425, the method 1400 may include aperiodically transmitting ornot transmitting the channel state information according to theinstructions received at block 1410. The operation(s) at block 1425 maybe performed using the wireless communication management module 620,720, 820, and/or 960 described with reference to FIGS. 6, 7, 8, and/or9, and/or the A-CSI reporting module 850 and/or A-CSI instructionmanagement module 865 described with reference to FIG. 8.

The method 1400 may be useful, in one respect, because the aperiodictransmission of channel state information is configurable. For example,the method for aperiodically transmitting or not transmitting channelstate information may be determined by a base station that does or doesnot want to receive the channel state information when a UE determinesthat a clear channel assessment failed for a frame for a componentcarrier in an unlicensed radio frequency spectrum band.

Thus, the method 1400 may provide for wireless communication. It shouldbe noted that the method 1400 is just one implementation and that theoperations of the method 1400 may be rearranged or otherwise modifiedsuch that other implementations are possible.

FIG. 15 is a flow chart illustrating an example of a method 1500 forwireless communication, in accordance with various aspects of thepresent disclosure. For clarity, the method 1500 is described below withreference to aspects of one or more of the UEs 115, 215, and/or 915described with reference to FIGS. 1, 2, and/or 9, and/or aspects of oneor more of the apparatuses 605, 705, and/or 805 described with referenceto FIGS. 6, 7, and/or 8. In some examples, a UE and/or apparatus mayexecute one or more sets of codes to control the functional elements ofthe base station and/or apparatus to perform the functions describedbelow.

At block 1505, the method 1500 may include receiving (e.g., from a basestation) a service via a component carrier. The component carrier may bein an unlicensed radio frequency spectrum band (e.g., a radio frequencyspectrum band for which apparatuses may need to contend for accessbecause the radio frequency spectrum band is available for unlicenseduse, such as a Wi-Fi radio frequency spectrum band). In some examples,the service (or one or more other services) may also be received via oneor more additional component carriers in the unlicensed radio frequencyspectrum band and/or one or more component carriers in a licensed radiofrequency spectrum band (e.g., a radio frequency spectrum band for whichapparatuses do not contend for access because the spectrum band islicensed to particular users for particular uses). The operation(s) atblock 1505 may be performed using the wireless communication managementmodule 620, 720, 820, and/or 960 described with reference to FIGS. 6, 7,8, and/or 9, and/or the component carrier management module 735 and/or840 described with reference to FIGS. 7 and/or 8.

At block 1510, the method 1500 may include determining whether a clearchannel assessment failed for a frame (e.g., a downlink frame or anuplink frame) for the component carrier. In some examples, thedetermining whether the clear channel assessment failed may be based atleast in part on a channel usage beacon signal, a reference signal for achannel state information report, and/or other information received forthe frame (any or all of which may be received from a base station overthe at least one component carrier in the unlicensed radio frequencyspectrum band). The operation(s) at block 1510 may be performed usingthe wireless communication management module 620, 720, 820, and/or 960described with reference to FIGS. 6, 7, 8, and/or 9, and/or the DCCAanalysis module 835 described with reference to FIG. 8.

At block 1515, the method 1500 may include measuring one or more signalstransmitted on the component carrier to estimate channel stateinformation of the component carrier in the unlicensed radio frequencyspectrum band. In some examples, the operation(s) at block 1515 mayoccur before the operation(s) at block 1510. The operation(s) at block1510 may be performed using the wireless communication management module620, 720, 820, and/or 960 described with reference to FIGS. 6, 7, 8,and/or 9, and/or the component carrier signal measurement module 740and/or 845 described with reference to FIGS. 7 and/or 8.

At block 1520, the method 1500 may include periodically transmitting thechannel state information regardless of whether a clear channelassessment failed for the frame for the component carrier. Theoperation(s) at block 1520 may be performed using the wirelesscommunication management module 620, 720, 820, and/or 960 described withreference to FIGS. 6, 7, 8, and/or 9, and/or the P-CSI reporting module870 and/or P-CSI semi-static configuration module 875 described withreference to FIG. 8.

The method 1500 may be useful, in one respect, because the periodictransmission of channel state information is not dependent on a UEcorrectly determining whether a clear channel assessment failed. Thismay provide better alignment between a base station and a UE that are incommunication over a component carrier.

Thus, the method 1500 may provide for wireless communication. It shouldbe noted that the method 1500 is just one implementation and that theoperations of the method 1500 may be rearranged or otherwise modifiedsuch that other implementations are possible.

FIG. 16 is a flow chart illustrating an example of a method 1600 forwireless communication, in accordance with various aspects of thepresent disclosure. For clarity, the method 1600 is described below withreference to aspects of one or more of the UEs 115, 215, and/or 915described with reference to FIGS. 1, 2, and/or 9, and/or aspects of oneor more of the apparatuses 605, 705, and/or 805 described with referenceto FIGS. 6, 7, and/or 8. In some examples, a UE and/or apparatus mayexecute one or more sets of codes to control the functional elements ofthe base station and/or apparatus to perform the functions describedbelow.

At block 1605, the method 1600 may include receiving (e.g., from a basestation) a service via a component carrier. The component carrier may bein an unlicensed radio frequency spectrum band (e.g., a radio frequencyspectrum band for which apparatuses may need to contend for accessbecause the radio frequency spectrum band is available for unlicenseduse, such as a Wi-Fi radio frequency spectrum band). In some examples,the service (or one or more other services) may also be received via oneor more additional component carriers in the unlicensed radio frequencyspectrum band and/or one or more component carriers in a licensed radiofrequency spectrum band (e.g., a radio frequency spectrum band for whichapparatuses do not contend for access because the spectrum band islicensed to particular users for particular uses). The operation(s) atblock 1605 may be performed using the wireless communication managementmodule 620, 720, 820, and/or 960 described with reference to FIGS. 6, 7,8, and/or 9, and/or the component carrier management module 735 and/or840 described with reference to FIGS. 7 and/or 8.

At block 1610, the method 1600 may include determining whether a clearchannel assessment failed for a frame for the component carrier. Theframe may be an uplink frame or a downlink frame. In some examples, thedetermining whether the clear channel assessment failed may be based atleast in part on a channel usage beacon signal, a reference signal for achannel state information report, and/or other information received forthe frame (any or all of which may be received from a base station overthe component carrier in the unlicensed radio frequency spectrum band).The operation(s) at block 1610 may be performed using the wirelesscommunication management module 620, 720, 820, and/or 960 described withreference to FIGS. 6, 7, 8, and/or 9, and/or the DCCA analysis module835 described with reference to FIG. 8.

Upon determining that the clear channel assessment succeeded for theframe for the component carrier, and at block 1615, the method 1600 mayinclude measuring one or more current signals transmitted on thecomponent carrier to estimate channel state information in theunlicensed radio frequency spectrum band (e.g., measuring one or moresignals associated with the frame for which the determination was madeat block 1610). The operation(s) at block 1615 may be performed usingthe wireless communication management module 620, 720, 820, and/or 960described with reference to FIGS. 6, 7, 8, and/or 9, and/or thecomponent carrier signal measurement module 740 and/or 845 describedwith reference to FIGS. 7 and/or 8.

Upon determining that the clear channel assessment failed for the framefor the component carrier, and at block 1620, the method 1600 mayinclude 1) retrieving measurements for one or more historic signalstransmitted on the component carrier to estimate channel stateinformation of the component carrier in the unlicensed radio frequencyspectrum band (e.g., retrieving measurements based on a measuring of oneor more historic signals associated with the component carrier toestimate channel state information), or 2) measuring one or more currentsignals associated with the component carrier to estimate channel stateinformation of the component carrier in the unlicensed radio frequencyspectrum band. In some examples, the operation(s) at block 1125 mayoccur before the operation(s) at block 1110. The operation(s) at block1125 may be performed using the wireless communication management module620, 720, 820, and/or 960 described with reference to FIGS. 6, 7, 8,and/or 9, and/or the component carrier signal measurement module 740and/or 845 described with reference to FIGS. 7 and/or 8.

At block 1625, the method 1600 may include periodically transmitting ornot transmitting the channel state information according to defaultreporting rules, as described, for example, with reference to FIG. 5.The operation(s) at block 1625 may be performed using the wirelesscommunication management module 620, 720, 820, and/or 960 described withreference to FIGS. 6, 7, 8, and/or 9, and/or the P-CSI reporting module870 described with reference to FIG. 8.

The method 1600 may be useful, in one respect, because the periodictransmission of channel state information is not dependent on a UEcorrectly determining whether a clear channel assessment failed.However, a base station receiving the channel state informationtransmitted at block 1625 may need to blindly detect which type ofchannel state information it receives from a UE. If a base stationcannot detect which type of channel state information it receives from aUE, the base station may have to discard the channel state information.

Thus, the method 1600 may provide for wireless communication. It shouldbe noted that the method 1600 is just one implementation and that theoperations of the method 1600 may be rearranged or otherwise modifiedsuch that other implementations are possible.

FIG. 17 is a flow chart illustrating an example of a method 1700 forwireless communication, in accordance with various aspects of thepresent disclosure. For clarity, the method 1700 is described below withreference to aspects of one or more of the UEs 115, 215, and/or 915described with reference to FIGS. 1, 2, and/or 9, and/or aspects of oneor more of the apparatuses 605, 705, and/or 805 described with referenceto FIGS. 6, 7, and/or 8. In some examples, a UE and/or apparatus mayexecute one or more sets of codes to control the functional elements ofthe base station and/or apparatus to perform the functions describedbelow.

At block 1705, the method 1700 may include receiving (e.g., from a basestation) a service via a component carrier. The component carrier may bein an unlicensed radio frequency spectrum band (e.g., a radio frequencyspectrum band for which apparatuses may need to contend for accessbecause the radio frequency spectrum band is available for unlicenseduse, such as a Wi-Fi radio frequency spectrum band). In some examples,the service (or one or more other services) may also be received via oneor more additional component carriers in the unlicensed radio frequencyspectrum band and/or one or more component carriers in a licensed radiofrequency spectrum band (e.g., a radio frequency spectrum band for whichapparatuses do not contend for access because the spectrum band islicensed to particular users for particular uses). The operation(s) atblock 1705 may be performed using the wireless communication managementmodule 620, 720, 820, and/or 960 described with reference to FIGS. 6, 7,8, and/or 9, and/or the component carrier management module 735 and/or840 described with reference to FIGS. 7 and/or 8.

At block 1710, the method 1700 may include determining whether a clearchannel assessment failed for a frame for the component carrier. In someexamples, the determining whether the clear channel assessment failedmay be based at least in part on a channel usage beacon signal, areference signal for a channel state information report, and/or otherinformation received for the frame (any or all of which may be receivedfrom a base station over the component carrier in the unlicensed radiofrequency spectrum band). In some examples, the frame for the componentcarrier may be a downlink frame or an uplink frame. The operation(s) atblock 1710 may be performed using the wireless communication managementmodule 620, 720, 820, and/or 960 described with reference to FIGS. 6, 7,8, and/or 9, and/or the DCCA analysis module 835 described withreference to FIG. 8.

At block 1715, the method 1700 may include measuring one or more signalstransmitted on the component carrier to estimate channel stateinformation of the component carrier in the unlicensed radio frequencyspectrum band. In some examples, the operation(s) at block 1715 mayoccur before the operation(s) at block 1710. The operation(s) at block1710 may be performed using the wireless communication management module620, 720, 820, and/or 960 described with reference to FIGS. 6, 7, 8,and/or 9, and/or the component carrier signal measurement module 740and/or 845 described with reference to FIGS. 7 and/or 8.

At block 1720, the method 1700 may include periodically transmitting thechannel state information. In some examples, the channel stateinformation may include an indication used to identify the componentcarrier associated with the channel state information regardless ofwhether the clear channel assessment failed for the frame for thecomponent carrier. In other examples, the channel state information mayinclude the indication used to identify the component carrier associatedwith the channel state information when the clear channel assessmentperformed at block 1710 is determined to have failed.

In some examples, the indication used to identify the component carrierassociated with the channel state information may explicitly identifythe component carrier associated with the channel state information.

In some examples, the indication used to identify the component carrierassociated with the channel state information may implicitly identifythe component carrier associated with the channel state information. Forexample, the indication used to identify the component carrierassociated with the channel state information may include a scramblingpattern (e.g., a scrambling code) associated with the component carrierassociated with the channel state information. In one particularexample, the scrambling pattern may include a first scrambling patternwhen the channel state information is associated with a primary cell,and the scrambling pattern may include a second scrambling pattern whenthe channel state information is associated with a secondary cell.

In another example, the indication used to identify the componentcarrier associated with the channel state information may include a ratematching for a multiplexed PUCCH and PUSCH and/or a PUCCH resourcelocation. For example, a first rate matching may be used when thechannel state information is associated with a primary cell, and asecond rate matching may be used when the channel state information isassociated with a secondary cell.

The operation(s) at block 1720 may be performed using the wirelesscommunication management module 620, 720, 820, and/or 960 described withreference to FIGS. 6, 7, 8, and/or 9, and/or the P-CSI reporting module870 and/or P-CSI component carrier indication module 880 described withreference to FIG. 8.

The method 1700 may be useful, in one respect, because channel stateinformation is periodically transmitted with an indication that removesambiguity regarding the component carrier to which it pertains.

Thus, the method 1700 may provide for wireless communication. It shouldbe noted that the method 1700 is just one implementation and that theoperations of the method 1700 may be rearranged or otherwise modifiedsuch that other implementations are possible.

FIG. 18 is a flow chart illustrating an example of a method 1800 forwireless communication, in accordance with various aspects of thepresent disclosure. For clarity, the method 1800 is described below withreference to aspects of one or more of the UEs 115, 215, and/or 915described with reference to FIGS. 1, 2, and/or 9, and/or aspects of oneor more of the apparatuses 605, 705, and/or 805 described with referenceto FIGS. 6, 7, and/or 8. In some examples, a UE and/or apparatus mayexecute one or more sets of codes to control the functional elements ofthe base station and/or apparatus to perform the functions describedbelow.

At block 1805, the method 1800 may include receiving (e.g., from a basestation) a service via a component carrier. The component carrier may bein an unlicensed radio frequency spectrum band (e.g., a radio frequencyspectrum band for which apparatuses may need to contend for accessbecause the radio frequency spectrum band is available for unlicenseduse, such as a Wi-Fi radio frequency spectrum band). In some examples,the service (or one or more other services) may also be received via oneor more additional component carriers in the unlicensed radio frequencyspectrum band and/or one or more component carriers in a licensed radiofrequency spectrum band (e.g., a radio frequency spectrum band for whichapparatuses do not contend for access because the spectrum band islicensed to particular users for particular uses). The operation(s) atblock 1805 may be performed using the wireless communication managementmodule 620, 720, 820, and/or 960 described with reference to FIGS. 6, 7,8, and/or 9, and/or the component carrier management module 735 and/or840 described with reference to FIGS. 7 and/or 8.

At block 1810, the method 1800 may include determining whether a clearchannel assessment failed for a frame for the component carrier. In someexamples, the determining whether the clear channel assessment failedmay be based at least in part on a channel usage beacon signal, areference signal for a channel state information report, and/or otherinformation received for the frame (any or all of which may be receivedfrom a base station over the component carrier in the unlicensed radiofrequency spectrum band). In some examples, the frame for the componentcarrier may be a downlink frame. In other examples, the frame for thecomponent carrier may be an uplink frame. The operation(s) at block 1810may be performed using the wireless communication management module 620,720, 820, and/or 960 described with reference to FIGS. 6, 7, 8, and/or9, and/or the DCCA analysis module 835 described with reference to FIG.8.

At block 1815, the method 1800 may include measuring one or more signalstransmitted on the component carrier to estimate channel stateinformation of the component carrier in the unlicensed radio frequencyspectrum band. In some examples, the operation(s) at block 1815 mayoccur before the operation(s) at block 1810. The operation(s) at block1810 may be performed using the wireless communication management module620, 720, 820, and/or 960 described with reference to FIGS. 6, 7, 8,and/or 9, and/or the component carrier signal measurement module 740and/or 845 described with reference to FIGS. 7 and/or 8.

At block 1820, the method 1800 may include determining whether acondition is met. In one example, the condition may include a samepayload size for at least two alternate channel state informationtransmissions. A same payload size may exist, for example, when achannel state information transmission for the component carrier usesthe same transmission mode and the same number of transmit antennasand/or receive antennas as a channel state information transmission forat least one other component carrier. The operation(s) at block 1820 maybe performed using the wireless communication management module 620,720, 820, and/or 960 described with reference to FIGS. 6, 7, 8, and/or9, and/or the P-CSI condition monitoring module 885 described withreference to FIG. 8.

Upon determining that the condition is not met, and at block 1825, themethod 1800 may include periodically transmitting the channel stateinformation according to default reporting rules, as described, forexample, with reference to FIG. 5. The operation(s) at block 1825 may beperformed using the wireless communication management module 620, 720,820, and/or 960 described with reference to FIGS. 6, 7, 8, and/or 9,and/or the P-CSI reporting module 870 and/or P-CSI condition monitoringmodule 885 described with reference to FIG. 8.

Upon determining that the condition is met, and at block 1830, themethod 1800 may include periodically transmitting the channel stateinformation with an indication used to identify the component carrierassociated with the channel state information. The operation(s) at block1830 may be performed using the wireless communication management module620, 720, 820, and/or 960 described with reference to FIGS. 6, 7, 8,and/or 9, and/or the P-CSI reporting module 870 and/or P-CSI conditionmonitoring module 885 described with reference to FIG. 8.

The operations at block 1820, block 1825, and/or block 1830 may be usedto lessen or remove ambiguity for a base station that receives thechannel state information transmitted in accordance with the method1800. In particular, when the channel state information for at least afirst component carrier and the channel state information transmissionfor at least a second component carrier have the same payload size, themethod 1800 may transmit channel state information with an indicationused to identify the component carrier associated with the channel stateinformation.

In some examples, the indication used to identify the component carrierassociated with the channel state information may explicitly identifythe component carrier associated with the channel state information.

In some examples, the indication used to identify the component carrierassociated with the channel state information may implicitly identifythe component carrier associated with the channel state information. Forexample, the indication used to identify the component carrierassociated with the channel state information may include a scramblingpattern (e.g., a scrambling code) associated with the component carrierassociated with the channel state information. In one particularexample, the scrambling pattern may include a first scrambling patternwhen the channel state information is associated with a primary cell,and the scrambling pattern may include a second scrambling pattern whenthe channel state information is associated with a secondary cell.

In another example, the indication used to identify the componentcarrier associated with the channel state information may include a ratematching for a multiplexed PUCCH and PUSCH and/or a PUCCH resourcelocation. For example, a first rate matching may be used when thechannel state information is associated with a primary cell, and asecond rate matching may be used when the channel state information isassociated with a secondary cell.

The method 1800 may be useful, in one respect, because channel stateinformation may be periodically transmitted with an indication thatremoves ambiguity regarding the component carrier to which it pertains.

Thus, the method 1800 may provide for wireless communication. It shouldbe noted that the method 1800 is just one implementation and that theoperations of the method 1800 may be rearranged or otherwise modifiedsuch that other implementations are possible.

In some examples, aspects of one or more of the methods 1000, 1100,1200, 1300, 1400, 1500, 1600, 1700, and/or 1800 may be combined.

The detailed description set forth above in connection with the appendeddrawings describes examples and does not represent the only examplesthat may be implemented or that are within the scope of the claims. Theterms “example” and “exemplary,” when used in this description, mean“serving as an example, instance, or illustration,” and not “preferred”or “advantageous over other examples.” The detailed description includesspecific details for the purpose of providing an understanding of thedescribed techniques. These techniques, however, may be practicedwithout these specific details. In some instances, well-known structuresand apparatuses are shown in block diagram form in order to avoidobscuring the concepts of the described examples.

Information and signals may be represented using any of a variety ofdifferent technologies and techniques. For example, data, instructions,commands, information, signals, bits, symbols, and chips that may bereferenced throughout the above description may be represented byvoltages, currents, electromagnetic waves, magnetic fields or particles,optical fields or particles, or any combination thereof.

The various illustrative blocks and modules described in connection withthe disclosure herein may be implemented or performed with ageneral-purpose processor, a digital signal processor (DSP), an ASIC, anFPGA or other programmable logic device, discrete gate or transistorlogic, discrete hardware components, or any combination thereof designedto perform the functions described herein. A general-purpose processormay be a microprocessor, but in the alternative, the processor may beany conventional processor, controller, microcontroller, or statemachine. A processor may also be implemented as a combination ofcomputing devices, e.g., a combination of a DSP and a microprocessor,multiple microprocessors, one or more microprocessors in conjunctionwith a DSP core, or any other such configuration.

The functions described herein may be implemented in hardware, softwareexecuted by a processor, firmware, or any combination thereof. Ifimplemented in software executed by a processor, the functions may bestored on or transmitted over as one or more instructions or code on anon-transitory computer-readable medium. Other examples andimplementations are within the scope and spirit of the disclosure andappended claims. For example, due to the nature of software, functionsdescribed above can be implemented using software executed by aprocessor, hardware, firmware, hardwiring, or combinations of any ofthese. Features implementing functions may also be physically located atvarious positions, including being distributed such that portions offunctions are implemented at different physical locations. Also, as usedherein, including in the claims, “or” as used in a list of itemsprefaced by “at least one of” indicates a disjunctive list such that,for example, a list of “at least one of A, B, or C” means A or B or C orAB or AC or BC or ABC (i.e., A and B and C).

Computer-readable media includes both computer storage media andcommunication media including any medium that facilitates transfer of acomputer program from one place to another. A storage medium may be anyavailable medium that can be accessed by a general purpose or specialpurpose computer. By way of example, and not limitation,computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or otheroptical disk storage, magnetic disk storage or other magnetic storagedevices, or any other medium that can be used to carry or store desiredprogram code means in the form of instructions or data structures andthat can be accessed by a general-purpose or special-purpose computer,or a general-purpose or special-purpose processor. Also, any connectionis properly termed a computer-readable medium. For example, if thesoftware is transmitted from a website, server, or other remote sourceusing a coaxial cable, fiber optic cable, twisted pair, digitalsubscriber line (DSL), or wireless technologies such as infrared, radio,and microwave, then the coaxial cable, fiber optic cable, twisted pair,DSL, or wireless technologies such as infrared, radio, and microwave areincluded in the definition of medium. Disk and disc, as used herein,include compact disc (CD), laser disc, optical disc, digital versatiledisc (DVD), floppy disk and Blu-ray disc where disks usually reproducedata magnetically, while discs reproduce data optically with lasers.Combinations of the above are also included within the scope ofcomputer-readable media.

The previous description of the disclosure is provided to enable aperson skilled in the art to make or use the disclosure. Variousmodifications to the disclosure will be readily apparent to thoseskilled in the art, and the generic principles defined herein may beapplied to other variations without departing from the spirit or scopeof the disclosure. Throughout this disclosure the term “example” or“exemplary” indicates an example or instance and does not imply orrequire any preference for the noted example. Thus, the disclosure isnot to be limited to the examples and designs described herein but is tobe accorded the widest scope consistent with the principles and novelfeatures disclosed herein.

What is claimed is:
 1. A method of wireless communication at a userequipment (UE), comprising: receiving downlink control information(DCI); determining, based at least in part on the DCI, that at least onecondition associated with reporting channel state information (CSI) issatisfied; and selecting, based at least in part on determining that theat least one condition is satisfied, a CSI subframe associated withreporting the CSI.
 2. The method of claim 1, further comprising:reporting, based at least in part on the selecting, the CSI to a basestation.
 3. The method of claim 1, wherein determining that the at leastone condition is satisfied is based at least in part on a CSI subframevalue.
 4. The method of claim 1, wherein the DCI comprises an indicationassociated with at least one of transmitting the CSI according to afirst mode or not transmitting the CSI according to the first mode,wherein the selecting is based at least in part on the indication. 5.The method of claim 4, wherein the indication comprises at least onetrigger bit comprising at least one of a first bit associated with thetransmitting the CSI according to the first mode or a second bitassociated with not transmitting the CSI according to the first mode. 6.The method of claim 5, wherein transmitting the CSI according to thefirst mode comprises aperiodically transmitting the CSI and nottransmitting the CSI according to the first mode comprises notaperiodically transmitting the CSI.
 7. The method of claim 5, whereinthe at least one trigger bit is distinct from a CSI triggering bit. 8.The method of claim 7, wherein the at least one trigger bit comprises atleast a 0 value state or a 1 value state.
 9. The method of claim 8,wherein for the transmitting the CSI according to the first mode the atleast one trigger bit comprises the 1 value state.
 10. The method ofclaim 9, wherein the CSI subframe comprises a downlink subframe.
 11. Themethod of claim 4, wherein for not transmitting the CSI the CSI subframeis associated with one of a DL subframe or a special subframe.
 12. Themethod of claim 3, wherein the CSI subframe value is associated with apayload size of the CSI subframe.
 13. The method of claim 1, wherein theDCI is received from a base station configured to transmit in a carrieraggregation mode based at least in part on utilizing both a licensedradio frequency spectrum band and an unlicensed radio frequency spectrumband.
 14. The method of claim 13, wherein determining that the at leastone condition is satisfied is based at least in part on a CSI subframevalue.
 15. The method of claim 14, wherein the DCI comprises anindication associated with aperiodic CSI reporting and one of a 0 valuestate or a 1 value state.
 16. An apparatus for wireless communications,comprising: a processor; memory in electronic communication with theprocessor; and instructions stored in the memory, the instructions beingexecutable by the processor to: receive downlink control information(DCI); determine, based at least in part on the DCI, that at least onecondition associated with reporting channel state information (CSI) issatisfied; and select, based at least in part on determining that the atleast one condition is satisfied, a CSI subframe associated withreporting the CSI.
 17. The apparatus of claim 16, wherein theinstructions executable by the processor to determine that the clearchannel assessment failed for the time interval further compriseinstructions executable by the processor to: reporting, based at leastin part on the selecting, the CSI to a base station.
 18. The apparatusof claim 16, wherein determining that the at least one condition issatisfied is based at least in part on a CSI subframe value.
 19. Theapparatus of claim 16, wherein the DCI comprises an indicationassociated with at least one of transmitting the CSI according to afirst mode or not transmitting the CSI according to the first mode,wherein the selecting is based at least in part on the indication. 20.The apparatus of claim 19, wherein the indication comprises at least onetrigger bit comprising at least one of a first bit associated with thetransmitting the CSI according to the first mode or a second bitassociated with not transmitting the CSI according to the first mode.21. The apparatus of claim 20, wherein transmitting the CSI according tothe first mode comprises aperiodically transmitting the CSI and nottransmitting the CSI according to the first mode comprises notaperiodically transmitting the CSI.
 22. The apparatus of claim 20,wherein the at least one trigger bit is distinct from a CSI triggeringbit.
 23. The apparatus of claim 22, wherein the at least one trigger bitcomprises at least a 0 value state or a 1 value state.
 24. The apparatusof claim 23, wherein for the transmitting the CSI according to the firstmode the at least one trigger bit comprises the 1 value state.
 25. Theapparatus of claim 24, wherein the CSI subframe comprises a downlinksubframe.
 26. The apparatus of claim 20, wherein for not transmittingthe CSI the CSI subframe is associated with one of a DL subframe or aspecial subframe.
 27. The apparatus of claim 19, wherein the CSIsubframe value is associated with a payload size of the CSI subframe.28. The apparatus of claim 16, wherein the DCI is received from a basestation configured to transmit in a carrier aggregation mode based atleast in part on utilizing both a licensed radio frequency spectrum bandand an unlicensed radio frequency spectrum band, and wherein determiningthat the at least one condition is satisfied is based at least in parton a CSI subframe value.
 29. An apparatus for wireless communications,comprising: means for receiving downlink control information (DCI);means for determining, based at least in part on the DCI, that at leastone condition associated with reporting channel state information (CSI)is satisfied; and means for selecting, based at least in part ondetermining that the at least one condition is satisfied, a CSI subframeassociated with reporting the CSI.
 30. A non-transitorycomputer-readable medium storing computer-executable code for wirelesscommunications, the code executable by a processor to: receive downlinkcontrol information (DCI); determine, based at least in part on the DCI,that at least one condition associated with reporting channel stateinformation (CSI) is satisfied; and select, based at least in part ondetermining that the at least one condition is satisfied, a CSI subframeassociated with reporting the CSI.